The likelihood of winter sprites over the Gulf Stream

NASA Astrophysics Data System (ADS)

Price, Colin; Burrows, William; King, Patrick

2002-11-01

With the recent introduction of the Canadian Lightning Detection Network (CLDN), it was revealed that during the winter months every year, the highest lightning activity within the network occurs over the Gulf Stream, southeast of Nova Scotia. These storms over the Gulf Stream, in addition to being of importance to trans-Atlantic shipping and aviation, have an unusually high fraction of positive polarity lightning, with unusually large peak currents. Such intense positive lightning flashes are known to generate transient luminous events (TLEs) such as sprites and elves in the upper atmosphere. It is found that many of these large positive discharges produce extremely low frequency (ELF) electromagnetic radiation detected at a field station in the Negev Desert, Israel, 8000 km away, in agreement with previously documented sprite observations. Since these winter storms occur in the same location every year, it provides a good opportunity for field experiments focused on studying winter sprites and oceanic thunderstorms.

Biochemical properties of a novel 28KDA protein tyrosine kinase partially purified from the particulate fraction of rat spleen.

PubMed

Borowski, P; Medem, S; Laufs, R

1993-12-15

In this report we present some of the biochemical properties of the enzyme, here called pp28(PTK), isolated from particulate fraction of rat spleen (1). The kinase is very susceptible for polyions as regulators of the enzymatic activity. The polyanions like dextran sulfate or heparin inhibited, and polycations such as spermidin, protamin, poly-L-lysine and some random polypeptides containing tyrosine besides a basic amino acid, stimulated the enzyme markedly. The kinase showed high sensitivity towards class IA salts. In the casein phosphorylation reaction the apparent Km value for ATP was 4 microM. An unusual property is associated with autophosphorylation which leads to a reduced activity towards external substrates. Some kinase inhibitors described in the literature were tested for their potency.

Elevated propionate and butyrate in fecal ferments of hydrolysates generated by oxalic acid treatment of corn bran arabinoxylan.

PubMed

Rumpagaporn, Pinthip; Reuhs, Brad L; Cantu-Jungles, Thaisa M; Kaur, Amandeep; Patterson, John A; Keshavarzian, Ali; Hamaker, Bruce R

2016-12-07

Previous work in our laboratory showed that alkali-solubilized corn arabinoxylan (CAX) has a slow initial, but later complete, in vitro human fecal fermentation. CAX and a moderately high molecular weight hydrolysate (CH) were propiogenic, and produced low levels of butyrate. Here, we show that oxalic acid-generated hydrolysates from CAX, which include a large xylooligosaccharide, and free arabinose fractions, increased short chain fatty acid (SCFA) production, which included relatively high levels of both propionate and butyrate, an unusual SCFA combination. Hydrolytic degradation of CAX by acid hydrolysis (0.05 M oxalic acid at 100 °C for 2 h) and subsequent graded ethanol precipitations were used to obtain mixtures with different molecular weight ranges. Ethanol-precipitated fractions (F 0-65%, F 65-75%, F 75-85%) were mostly lower than 100 kDa and F > 85% was composed of monosaccharides and oligosaccharides of DP 2-8. Oxalic acid treatment caused the removal of all single arabinose unit branch chains and some di/trisaccharide branch chains, producing lightly substituted xylan backbone fragments, most of which were in the oligosaccharide (DP < 10) size range. In vitro human fecal fermentation analyses showed all oxalic acid-hydrolysate fractions were slower fermenting than fructooligosaccharides (FOS), but produced similar or higher amounts of total SCFAs. Butyrate production in two hydrolyzate fractions was double that of CH, while propionate levels remained relatively high.

Collagen in the spicule organic matrix of the gorgonian Leptogorgia virgulata

NASA Technical Reports Server (NTRS)

Kingsley, R. J.; Tsuzaki, M.; Watabe, N.; Mechanic, G. L.

1990-01-01

Decalcification of the calcareous spicules from the gorgonian Leptogorgia virgulata reveals an organic matrix that may be divided into water insoluble and soluble fractions. The insoluble fraction displays characteristics typical of collagen, which is an unusual component of an invertebrate calcium carbonate structure. This matrix fraction exhibits a collagenous amino acid profile and behavior upon SDS-PAGE. Furthermore, the reducible crosslink, dihydroxylysinonorleucine (DHLNL), is detected in this fraction. The composition of the matrix varies seasonally; i.e., the collagenous composition is most prevalent in the summer. These results indicate that the insoluble matrix is a dynamic structure. Potential roles of this matrix in spicule calcification are discussed.

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.

Unusual DNA Structures Associated With Germline Genetic Activity in Caenorhabditis elegans

PubMed Central

Fire, Andrew; Alcazar, Rosa; Tan, Frederick

2006-01-01

We describe a surprising long-range periodicity that underlies a substantial fraction of C. elegans genomic sequence. Extended segments (up to several hundred nucleotides) of the C. elegans genome show a strong bias toward occurrence of AA/TT dinucleotides along one face of the helix while little or no such constraint is evident on the opposite helical face. Segments with this characteristic periodicity are highly overrepresented in intron sequences and are associated with a large fraction of genes with known germline expression in C. elegans. In addition to altering the path and flexibility of DNA in vitro, sequences of this character have been shown by others to constrain DNA∷nucleosome interactions, potentially producing a structure that could resist the assembly of highly ordered (phased) nucleosome arrays that have been proposed as a precursor to heterochromatin. We propose a number of ways that the periodic occurrence of An/Tn clusters could reflect evolution and function of genes that express in the germ cell lineage of C. elegans. PMID:16648589

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.

Nuclear Forensics and Radiochemistry: Chemistry

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

Rundberg, Robert S.

The chemical behavior of radioactive elements can differ from conventional wisdom because the number of atoms can be unusually small. Kinetic effects and unusual oxidation states are phenomena that make radiochemistry different from conventional analytic chemistry. The procedures developed at Los Alamos are designed to minimize these effects and provide reproducible results over a wide range of sample types. The analysis of nuclear debris has the additional complication of chemical fractionation and the incorporation of environmental contaminants. These are dealt with through the use of three component isotope ratios and the use of appropriate end members.

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.

Mineralogy and petrography of HAL, an isotopically-unusual Allende inclusion

NASA Technical Reports Server (NTRS)

Allen, J. M.; Grossman, L.; Lee, T.; Wasserburg, G. J.

1980-01-01

Results of a detailed mineralogical and textural study of the HAL (Hibonite ALlende) inclusion of the Allende meteorite, which has been found to exhibit no Mg-26 excesses despite very high Al-27/Mg-24 ratios and large fractionation effects with small nuclear effects in its Ca, are reported. The inclusion is found to consist of three up to 1-mm diameter hibonite crystals partially surrounded by a black rim resembling a devitrified glass and containing an anisotropic Al-Fe oxide, which is in turn surrounded by a 2-mm thick friable rim sequence consisting of five layers distinguishable by mineral composition. From the available evidence, it is concluded that each of the layers of the friable rim formed by the accretion of an assemblage of condensate grains rather than by the complete reaction of a HAL precursor with a nebular gas, thus explaining its unusual isotopic characteristics and supporting the conclusion that the solar nebular contained isotopically-distinct reservoirs.

Energy Gaps and Layer Polarization of Integer and Fractional Quantum Hall States in Bilayer Graphene.

PubMed

Shi, Yanmeng; Lee, Yongjin; Che, Shi; Pi, Ziqi; Espiritu, Timothy; Stepanov, Petr; Smirnov, Dmitry; Lau, Chun Ning; Zhang, Fan

2016-02-05

Owing to the spin, valley, and orbital symmetries, the lowest Landau level in bilayer graphene exhibits multicomponent quantum Hall ferromagnetism. Using transport spectroscopy, we investigate the energy gaps of integer and fractional quantum Hall (QH) states in bilayer graphene with controlled layer polarization. The state at filling factor ν=1 has two distinct phases: a layer polarized state that has a larger energy gap and is stabilized by high electric field, and a hitherto unobserved interlayer coherent state with a smaller gap that is stabilized by large magnetic field. In contrast, the ν=2/3 quantum Hall state and a feature at ν=1/2 are only resolved at finite electric field and large magnetic field. These results underscore the importance of controlling layer polarization in understanding the competing symmetries in the unusual QH system of BLG.

Particle size effect on strength, failure, and shock behavior in polytetrafluoroethylene-Al-W granular composite materials

NASA Astrophysics Data System (ADS)

Herbold, E. B.; Nesterenko, V. F.; Benson, D. J.; Cai, J.; Vecchio, K. S.; Jiang, F.; Addiss, J. W.; Walley, S. M.; Proud, W. G.

2008-11-01

The variation of metallic particle size and sample porosity significantly alters the dynamic mechanical properties of high density granular composite materials processed using a cold isostatically pressed mixture of polytetrafluoroethylene (PTFE), aluminum (Al), and tungsten (W) powders. Quasistatic and dynamic experiments are performed with identical constituent mass fractions with variations in the size of the W particles and pressing conditions. The relatively weak polymer matrix allows the strength and fracture modes of this material to be governed by the granular type behavior of agglomerated metal particles. A higher ultimate compressive strength was observed in relatively high porosity samples with small W particles compared to those with coarse W particles in all experiments. Mesoscale granular force chains of the metallic particles explain this unusual phenomenon as observed in hydrocode simulations of a drop-weight test. Macrocracks forming below the critical failure strain for the matrix and unusual behavior due to a competition between densification and fracture in dynamic tests of porous samples were also observed. Numerical modeling of shock loading of this granular composite material demonstrated that the internal energy, specifically thermal energy, of the soft PTFE matrix can be tailored by the W particle size distribution.

Unusual ruby-sapphire transition in alluvial megacrysts, Cenozoic basaltic gem field, New England, New South Wales, Australia

NASA Astrophysics Data System (ADS)

Sutherland, Frederick L.; Graham, Ian T.; Harris, Stephen J.; Coldham, Terry; Powell, William; Belousova, Elena A.; Martin, Laure

2017-05-01

Rare ruby crystals appear among prevailing sapphire crystals mined from placers within basaltic areas in the New England gem-field, New South Wales, Australia. New England ruby (NER) has distinctive trace element features compared to those from ruby elsewhere in Australia and indeed most ruby from across the world. The NER suite includes ruby (up to 3370 ppm Cr), pink sapphire (up to 1520 ppm Cr), white sapphire (up to 910 ppm) and violet, mauve, purple, or bluish sapphire (up to 1410 ppm Cr). Some crystals show outward growth banding in this respective colour sequence. All four colour zones are notably high in Ga (up to 310 ppm) and Si (up to 1820 ppm). High Ga and Ga/Mg values are unusual in ruby and its trace element plots (laser ablation-inductively coupled plasma-mass spectrometry) and suggests that magmatic-metasomatic inputs were involved in the NER suite genesis. In situ oxygen isotope analyses (secondary ion mass spectrometry) across the NER suite colour range showed little variation (n = 22; δ18O = 4.4 ± 0.4, 2σ error), and are values typical for corundum associated with ultramafic/mafic rocks. The isolated NER xenocryst suite, corroded by basalt transport and with few internal inclusions, presents a challenge in deciphering its exact origin. Detailed consideration of its high Ga chemistry in relation to the known geology of the surrounding region was used to narrow down potential sources. These include Late Palaeozoic-Triassic fractionated I-type granitoid magmas or Mesozoic-Cenozoic felsic fractionates from basaltic magmas that interacted with early Palaeozoic Cr-bearing ophiolite bodies in the New England Orogen. Other potential sources may lie deeper within lower crust-mantle metamorphic assemblages, but need to match the anomalous high-Ga geochemistry of the New England ruby suite.

Runge-Lenz vector, accidental SU(2) symmetry, and unusual multiplets for motion on a cone

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

Al-Hashimi, M.H.; Wiese, U.-J.

2008-01-15

We consider a particle moving on a cone and bound to its tip by 1/r or harmonic oscillator potentials. When the deficit angle of the cone divided by 2{pi} is a rational number, all bound classical orbits are closed. Correspondingly, the quantum system has accidental degeneracies in the discrete energy spectrum. An accidental SU(2) symmetry is generated by the rotations around the tip of the cone as well as by a Runge-Lenz vector. Remarkably, some of the corresponding multiplets have fractional 'spin' and unusual degeneracies.

Hot regions of labile and stable soil organic carbon in Germany - Spatial variability and driving factors

NASA Astrophysics Data System (ADS)

Vos, Cora; Jaconi, Angélica; Jacobs, Anna; Don, Axel

2018-06-01

Atmospheric carbon dioxide levels can be mitigated by sequestering carbon in the soil. Sequestration can be facilitated by agricultural management, but its influence is not the same on all soil carbon pools, as labile pools with a high turnover may be accumulated much faster but are also more vulnerable to losses. The aims of this study were to (1) assess how soil organic carbon (SOC) is distributed among SOC fractions on a national scale in Germany, (2) identify factors influencing this distribution and (3) identify regions with high vulnerability to SOC losses. The SOC content and proportion of two different SOC fractions were estimated for more than 2500 mineral topsoils (< 87 g kg-1 SOC) covering Germany, using near-infrared reflectance spectroscopy. Drivers of the spatial variability in SOC fractions were determined using the machine learning algorithm cforest. The SOC content and proportions of fractions were predicted with good accuracy (SOC content: R2 = 0.87-0.90; SOC proportions: R2 = 0.83; ratio of performance to deviation (RPD): 2.4-3.2). The main explanatory variables for the distribution of SOC among the fractions were soil texture, bulk soil C / N ratio, total SOC content and pH. For some regions, the drivers were linked to the land-use history of the sites. Arable topsoils in central and southern Germany were found to contain the highest proportions and contents of stable SOC fractions, and therefore have the lowest vulnerability to SOC losses. North-western Germany contains an area of sandy soils with unusually high SOC contents and high proportions of light SOC fractions, which are commonly regarded as representing a labile carbon pool. This is true for the former peat soils in this area, which have already lost and are at high risk of losing high proportions of their SOC stocks. Those black sands can, however, also contain high amounts of stable SOC due to former heathland vegetation and need to be treated and discussed separately from non-black sand agricultural soils. Overall, it was estimated that, in large areas all over Germany, over 30 % of SOC is stored in easily mineralisable forms. Thus, SOC-conserving management of arable soils in these regions is of great importance.

Mesozoic high-Mg andesites from the Daohugou area, Inner Mongolia: Upper-crustal fractional crystallization of parental melt derived from metasomatized lithospheric mantle wedge

NASA Astrophysics Data System (ADS)

Meng, Fanxue; Gao, Shan; Song, Zhaojun; Niu, Yaoling; Li, Xuping

2018-03-01

Mineral chemistry, major- and trace-element data, zircon U-Pb ages, and Sr-Nd isotopic data are presented for a suite of volcanic rocks from the Daohugou area, Ningcheng City, Inner Mongolia, on the northern margin of the North China Craton. Samples from the suite are of basaltic andesite to rhyolite in composition, with the rocks containing <60 wt% SiO2 have high MgO, Cr, and Ni contents, and classify as high-Mg andesites (HMAs). Zircons from a rhyolite yielded weighted mean 206Pb/238U age of 164 ± 1 Ma, indicating that the Daohugou volcanic suite is coeval with the Tiaojishan Formation of northern Hebei and western Liaoning Province. The HMAs have similar enriched-mantle I (EMI)-type isotopic compositions to each other, with low εNd (t) values, moderate (87Sr/86Sr) i ratios, enrichment in LREEs relative to LILEs, and depletion in HFSEs (e.g., Nb, Ta, Ti), indicating formation through protracted fractional crystallization of a common parental magma. The unusually low CaO contents and CaO/FeO ratios of olivine phenocrysts in the HMAs suggest that the parental melt was subduction-related. The results of Rhyolite-MELTS modelling indicates that HMAs may form through upper-crustal fractional crystallization from arc basalts. Therefore, the Daohugou HMAs were most likely formed through fractional crystallization of a parental melt derived from metasomatized lithospheric mantle at crustal depths. The addition of "water" to the cratonic keel may have played a key role in the destruction of the North China Craton.

Separation and quantitation of colour pigments of chili powder (Capsicum frutescens) by high-performance liquid chromatography-diode array detection.

PubMed

Cserháti, T; Forgács, E; Morais, M H; Mota, T; Ramos, A

2000-10-27

The performance of reversed-phase thin-layer (RP-TLC) and reversed-phase high-performance liquid chromatography (RP-HPLC) was compared for the separation and determination of the colour pigments of chili (Capsicum frutescens) powder using a wide variety of eluent systems. No separation of pigments was achieved in RP-TLC, however, it was established that tetrahydrofuran shows an unusually high solvent strength. RP-HPLC using water-methanol-acetonitrile gradient elution separated the chili pigments in many fractions. Diode array detection (DAD) indicated that yellow pigments are eluted earlier than the red ones and chili powder contains more yellow pigments than common paprika powders. It was established that the very different absorption spectra of pigments make the use of DAD necessary.

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.

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.

Diblock copolymers of polystyrene- b-poly(1,3-cyclohexadiene) exhibiting unique three-phase microdomain morphologies

DOE PAGES

Misichronis, Konstantinos; Chen, Jihua; Kahk, Jong K.; ...

2016-03-29

Here, the synthesis and molecular characterization of a series of conformationally asymmetric polystyrene-block-poly(1,3-cyclohexadiene) (PS- b-PCHD) diblock copolymers (PCHD: ~90% 1,4 and ~10% 1,2), by sequential anionic copolymerization high vacuum techniques, is reported. A wide range of volume fractions (0.27 ≤ Φ PS ≤ 0.91) was studied by transmission electron microscopy and small-angle X-ray scattering in order to explore in detail the microphase separation behavior of these flexible/semiflexible diblock copolymers. Unusual morphologies, consisting of PCHD core(PCHD-1,4)–shell(PCHD-1,2) cylinders in PS matrix and three-phase (PS, PCHD-1,4, PCHD-1,2) four-layer lamellae, were observed suggesting that the chain stiffness of the PCHD block and the strongmore » dependence of the interaction parameter χ on the PCHD microstructures are important factors for the formation of this unusual microphase separation behavior in PS- b-PCHD diblock copolymers. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 1564–1572« less

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.

Communication: Unusual structure and transport in ionic liquid-hexane mixtures

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

Liang, Min; Khatun, Sufia; Castner, Edward W., E-mail: ecastner@rci.rutgers.edu

2015-03-28

Ionic liquids having a sufficiently amphiphilic cation can dissolve large volume fractions of alkanes, leading to mixtures with intriguing properties on molecular length scales. The trihexyl(tetradecyl)phosphonium cation paired with the bis(trifluoromethylsulfonyl)amide anion provides an ionic liquid that can dissolve large mole fractions of hexane. We present experimental results on mixtures of n-C{sub 6}D{sub 14} with this ionic liquid. High-energy X-ray scattering studies reveal a persistence of the characteristic features of ionic liquid structure even for 80% dilution with n-C{sub 6}D{sub 14}. Nuclear magnetic resonance self-diffusion results reveal decidedly non-hydrodynamic behavior where the self-diffusion of the neutral, non-polar n-C{sub 6}D{sub 14}more » is on average a factor of 21 times faster than for the cation. Exploitation of the unique structural and transport properties of these mixtures may lead to new opportunities for designer solvents for enhanced chemical reactivity and interface science.« less

Spectral and temporal properties of the X-ray pulsar SMC X-1 at hard X-rays

NASA Technical Reports Server (NTRS)

Kunz, M.; Gruber, D. E.; Kendziorra, E .; Kretschmar, P.; Maisack, M.; Mony, B.; Staubert, R.; Doebereiner, S.; Englhauser, J.; Pietsch, W.

1993-01-01

The binary X-ray pulsar SMC X- 1 has been observed at hard X-rays with the High Energy X-Ray Experiment (HEXE) on nine occasions between Nov. 1987 and March 1989. A thin thermal bremsstrahlung fit to the phase averaged spectrum yields a plasma temperature (14.4 +/- 1.3) keV and a luminosity above (1.1 +/- 0.1) x 10 exp 38 erg/s in the 20-80 keV band. Pulse period values have been established for three observations, confirming the remarkably stable spin-up trend of SMC X-1. In one of the three observations the pulse profile was seen to deviate from a dominant double pulsation, while at the same time the pulsed fraction was unusually large. For one observation we determined for the first time the pulsed fraction in narrow energy bands. It increases with photon energy from about 20 percent up to over 60 percent in the energy range from 20 to 80 keV.

Communication: Unusual structure and transport in ionic liquid-hexane mixtures

DOE PAGES

Liang, Min; Khatun, Sufia; Castner, Edward W.

2015-03-28

Ionic liquids having a sufficiently amphiphilic cation can dissolve large volume fractions of alkanes, leading to mixtures with intriguing properties on molecular length scales. The trihexyl(tetradecyl)phosphonium cation paired with the bis(trifluoromethylsulfonyl)amide anion provides an ionic liquid that can dissolve large mole fractions of hexane. We present experimental results on mixtures of n-C 6D 14 with this ionic liquid. High- energy X-ray scattering studies reveal a persistence of the characteristic features of ionic liquid structure even for 80% dilution with n-C 6D 14. NMR self-diffusion results reveal decidedly non-hydrodynamic behavior where the self-diffusion of the neutral, non-polar n-C 6D 14 ismore » on average a factor of 21 times faster than for the cation. Exploitation of the unique structural and transport properties of these mixtures may lead to new opportunities for designer solvents for enhanced chemical reactivity and interface science.« less

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

Polysaccharides from the South African medicinal plant Artemisia afra: Structure and activity studies.

PubMed

Braünlich, Paula Marie; Inngjerdingen, Kari Tvete; Inngjerdingen, Marit; Johnson, Quinton; Paulsen, Berit Smestad; Mabusela, Wilfred

2018-01-01

Artemisia afra (Jacq. Ex. Willd), is an indigenous plant in South Africa and other parts of the African continent, where it is used as traditional medicine mostly for respiratory conditions. The objective of this study was to investigate the structural features of the polysaccharides from the leaves of this plant, as well as the biological activities of the polysaccharide fractions against the complement assay. Leaves of Artemisia afra were extracted sequentially with organic solvents (dichloromethane and methanol), 50% aqueous ethanol, and water at 50 and 100°C respectively. The polysaccharide extracts were fractionated by ion exchange chromatography and the resulting fractions were tested for biological activity against the complement fixation assay. Active fractions were further fractionated using gel filtration. Monosaccharide compositions and linkage analyses were determined for the relevant fractions. Polysaccharides were shown to be of the pectin type, and largely contain arabinogalactan, rhamnogalacturonan and homogalacturonan structural features. The presence of arabinogalactan type II features as suggested by methylation analysis was further confirmed by the ready precipitation of the relevant polysaccharides with the Yariv reagent. An unusual feature of some of these polysaccharides was the presence of relatively high levels of xylose as one of its monosaccharide constituents. Purified polysaccharide fractions were shown to possess higher biological activity than the selected standard in the complement assay. Digestion of these polysaccharides with an endo-polygalacturonase enzyme resulted in polymers with lower molecular weights as expected, but still with biological activity which exceeded that of the standard. Thus on the basis of these studies it may be suggested that immunomodulating properties probably contribute significantly to the health-promoting effects of this medicinal plant. Copyright © 2017 Elsevier B.V. All rights reserved.

Charge Fractionalization in the Two-Channel Kondo Effect

NASA Astrophysics Data System (ADS)

Landau, L. Aviad; Cornfeld, Eyal; Sela, Eran

2018-05-01

The phenomenon of charge fractionalization describes the emergence of novel excitations with fractional quantum numbers, as predicted in strongly correlated systems such as spin liquids. We elucidate that precisely such an unusual effect may occur in the simplest possible non-Fermi liquid, the two-channel Kondo effect. To bring this concept down to experimental test, we study nonequilibrium transport through a device realizing the charge two-channel Kondo critical point in a recent experiment by Iftikhar et al. [Nature (London) 526, 233 (2015), 10.1038/nature15384]. The shot noise at low voltages is predicted to result in a universal Fano factor e*/e =1 /2 . This allows us to experimentally identify elementary transport processes of emergent fermions carrying half-integer charge.

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.

Plastic fluctuations in empty crystals formed by cubic wireframe particles

NASA Astrophysics Data System (ADS)

McBride, John M.; Avendaño, Carlos

2018-05-01

We present a computer simulation study of the phase behavior of colloidal hard cubic frames, i.e., particles with nonconvex cubic wireframe geometry interacting purely by excluded volume. Despite the propensity of cubic wireframe particles to form cubic phases akin to their convex counterparts, these particles exhibit unusual plastic fluctuations in which a random and dynamic fraction of particles rotate around their lattice positions in the crystal lattice while the remainder of the particles remains fully ordered. We argue that this unexpected effect stems from the nonconvex geometry of the particles in which the faces of a particle can be penetrated by the vertices of the nearest neighbors even at high number densities.

Xylose-rich polysaccharides from the primary walls of embryogenic cell line of Pinus caribaea.

PubMed

Mollard, A; Domon, J M; David, H; Joseleau, J P

1997-08-01

Embryogenic cell lines of Pinus caribaea were isolated from somatic embryogenesis from zygotic embryos. Previous studies showed that the proteins and glycoproteins were characteristic of the embryogenic state. In the present work we were seeking typical feature in the polysaccharide from the cell walls of embryogenic calli at nine days of culture. Sequential extraction with water, ammonium oxalate, dimethyl sulfoxide, sodium borohydride and 4.3 M potassium hydroxide revealed that the extracted polysaccharides contained high proportions of arabinose and significant amounts of xylose. Fractionation of the hydrosoluble polymers on DEAE cellulose afforded a xylose-rich fraction (80% xylose, 24% glucose and lower properties of fucose and mannose). Methylation analysis and 13C-NMR spectra showed that the glycan backbone consisted of beta 1 --> 4 linked xylosyl residues Similar study of the fractions extracted respectively with DMSO and 4.3 M KOH showed the presence of polydisperse glycoxylans but excluded the presence of xyloglucan in significant amount. This could be a characteristic feature of embryogenic cells walls of Pinus caribaea or could be typical of cells grown as calluses. In the various fractions obtained from DEAE cellulose chromatography of the alkaline extract the infrequent occurrence of fucoxylans beside an arabinogalactan showed again the unusual nature of the cell wall polymers of this embryogenic lines, which seems to differ greatly from those found in the primary wall of cells from suspension cultures.

COMPOSITION OF CELLULAR MEMBRANES IN THE PANCREAS OF THE GUINEA PIG

PubMed Central

Meldolesi, J.; Jamieson, J. D.; Palade, G. E.

1971-01-01

The lipid composition of rough and smooth microsomal membranes, zymogen granule membranes, and a plasmalemmal fraction from the guinea pig pancreatic exocrine cell has been determined. As a group, membranes of the smooth variety (i.e., smooth microsomes, zymogen granule membranes, and the plasmalemma) were similar in their content of phospholipids, cholesterol and neutral lipids, and in the ratio of total lipids to membrane proteins. In contrast, rough microsomal membranes contained much less sphingomyelin and cholesterol and possessed a smaller lipid/protein ratio. All membrane fractions were unusually high in their content of lysolecithin (up to ∼20% of the total phospholipids) and of neutral lipids, especially fatty acids. The lysolecithin content was shown to be due to the hydrolysis of membrane lecithin by pancreatic lipase; the fatty acids, liberated by the action of lipase on endogenous triglyceride stores, are apparently scavenged by the membranes from the suspending media. Similar artifactually high levels of lysolecithin and fatty acids were noted in hepatic microsomes incubated with pancreatic postmicrosomal supernatant. E 600, an inhibitor of lipase, largely prevented the appearance of lysolecithin and fatty acids in pancreatic microsomes and in liver microsomes treated with pancreatic supernatant. PMID:5555573

Integrating seasonal optical and thermal infrared spectra to characterize urban impervious surfaces with extreme spectral complexity: a Shanghai case study

NASA Astrophysics Data System (ADS)

Wang, Wei; Yao, Xinfeng; Ji, Minhe

2016-01-01

Despite recent rapid advancement in remote sensing technology, accurate mapping of the urban landscape in China still faces a great challenge due to unusually high spectral complexity in many big cities. Much of this complication comes from severe spectral confusion of impervious surfaces with polluted water bodies and bright bare soils. This paper proposes a two-step land cover decomposition method, which combines optical and thermal spectra from different seasons to cope with the issue of urban spectral complexity. First, a linear spectral mixture analysis was employed to generate fraction images for three preliminary endmembers (high albedo, low albedo, and vegetation). Seasonal change analysis on land surface temperature induced from thermal infrared spectra and coarse component fractions obtained from the first step was then used to reduce the confusion between impervious surfaces and nonimpervious materials. This method was tested with two-date Landsat multispectral data in Shanghai, one of China's megacities. The results showed that the method was capable of consistently estimating impervious surfaces in highly complex urban environments with an accuracy of R2 greater than 0.70 and both root mean square error and mean average error less than 0.20 for all test sites. This strategy seemed very promising for landscape mapping of complex urban areas.

Radical chiral Floquet phases in a periodically driven Kitaev model and beyond

NASA Astrophysics Data System (ADS)

Po, Hoi Chun; Fidkowski, Lukasz; Vishwanath, Ashvin; Potter, Andrew C.

2017-12-01

We theoretically discover a family of nonequilibrium fractional topological phases in which time-periodic driving of a 2D system produces excitations with fractional statistics, and produces chiral quantum channels that propagate a quantized fractional number of qubits along the sample edge during each driving period. These phases share some common features with fractional quantum Hall states, but are sharply distinct dynamical phenomena. Unlike the integer-valued invariant characterizing the equilibrium quantum Hall conductance, these phases are characterized by a dynamical topological invariant that is a square root of a rational number, inspiring the label: radical chiral Floquet phases. We construct solvable models of driven and interacting spin systems with these properties, and identify an unusual bulk-boundary correspondence between the chiral edge dynamics and bulk "anyon time-crystal" order characterized by dynamical transmutation of electric-charge into magnetic-flux excitations in the bulk.

Non-insulated smooth motion, micro-needles RF fractional treatment for wrinkle reduction and lifting of the lower face: International study.

PubMed

Gold, Michael; Taylor, Mark; Rothaus, Kenneth; Tanaka, Yohei

2016-10-01

Skin aging occurs through both intrinsic and extrinsic processes. Fractional radiofrequency (RF) with a microneedling array is the newest form of fractional therapy to be useful in treating aging skin. The current study utilized a noninsulated fractional RF microneedling system. This multicenter clinical trial saw 49 patients complete 3 monthly treatments with the new fractional RF microneedling treatments and be followed for 3 months following their last treatment. Pain during treatment was recorded as well as overall improvement using a GAIS scale. Adverse events were also noted. Forty-nine patients completed all of the treatments and follow-ups. Mild to moderate erythema were reported immediately after treatment which lasted up to 12 hours after the treatment. Pain, as measured on a 1-10 VAS, was noted to 4, on average. The average Fitzpatrick's wrinkle scale score at baseline was 5.04 ± 1.22, 1 month after 3 treatments 3.829 ± 1.69 and 3 months after 3 treatments 3.5 ± 1.66. These results are statistically highly significant (correlated T-test, P < 0.001). Improvement was shown in 100% of patients while 65% of patients had significant improvement (GAIS levels 3-5). Significant skin tightening and skin lifting were also observed. No unusual adverse events were noted throughout the course of the study. This multicenter study showed significant wrinkle reduction, skin tightening, and lifting of the mid and lower face with the noninsulated fractional RF microneedling system. Lasers Surg. Med. 48:727-733, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

HIghMass—High H I Mass, H I-rich Galaxies at z ˜ 0: Combined H I and H2 Observations

NASA Astrophysics Data System (ADS)

Hallenbeck, Gregory; Huang, Shan; Spekkens, Kristine; Haynes, Martha P.; Giovanelli, Riccardo; Adams, Elizabeth A. K.; Brinchmann, Jarle; Carpenter, John; Chengalur, Jayaram; Hunt, Leslie K.; Masters, Karen L.; Saintonge, Amélie

2016-12-01

We present resolved {{H}} {{I}} and CO observations of three galaxies from the HIghMass sample, a sample of {{H}} {{I}}-massive ({M}{{H}{{I}}}\\gt {10}10 {M}⊙ ), gas-rich ({M}{{H}{{I}}} in the top 5% for their M *) galaxies identified in the ALFALFA survey. Despite their high gas fractions, these are not low-surface-brightness galaxies and have typical specific star formation rates (SFR/{M}* ) for their stellar masses. The three galaxies have normal SFRs for their {{{H}}}2 masses, but unusually short star formation efficiency scale lengths, indicating that the star formation bottleneck in these galaxies is in the conversion of {{H}} {{I}} to {{{H}}}2, not in converting {{{H}}}2 to stars. In addition, their dark matter spin parameters (λ) are above average, but not exceptionally high, suggesting that their star formation has been suppressed over cosmic time but is now becoming active, in agreement with prior Hα observations.

Traditionally used medicinal plants against uncomplicated urinary tract infections: Are unusual, flavan-4-ol- and derhamnosylmaysin derivatives responsible for the antiadhesive activity of extracts obtained from stigmata of Zea mays L. against uropathogenic E. coli and Benzethonium chloride as frequent contaminant faking potential antibacterial activities?

PubMed

Rafsanjany, Nasli; Sendker, Jandirk; Lechtenberg, Matthias; Petereit, Frank; Scharf, Birte; Hensel, Andreas

2015-09-01

The dried stigmata from Zea mays L. are used traditionally for the treatment of uncomplicated urinary tract infections. A recent screening has indicated that hydroalcoholic extract of the herbal material inhibits the adhesion of uropathogenic Escherichia coli (UPEC) to T24 bladder cells. For verification of these data EtOH-water (1:1) extracts from 4 different batches of Maydis stigmata were investigated. Within an in vitro adhesion assay (UPEC strain 2980 and human T24 bladder cells) a dose-dependent antiadhesive activity against UPEC was verified (IC50 1040μg/mL). Bioassay guided fractionation of M. stigmata, batch S1, by EtOH-water extraction, followed by chromatography on Sephadex LH20 revealed two active fractions (I and XI). Further purification of fraction I and structure elucidation of the isolated compound revealed the presence of significant amounts of the biocide benzethonium chloride as contaminant. Benzethonium chloride was also identified in subsequent investigations in 2 different batches of M. stigmata. The presence of such nondeclared and illegal contaminants in the herbal raw material market has to be discussed intensively. From benzethonium-free raw material (batch S2) as well as from batch S1 fraction XI was further fractionated by MPLC and preparative HPLC, leading to a still complex subfraction XIG, which was analyzed by UHPLC/+ESI-QTOF-MS analysis. Advanced data processing and species-metabolite relationship database revealed the tentatively existence of the unusual C-glycosidic flavones derhamnosylmaysin (6), 3'-deoxyrhamnosylmaysin (4), 3'-O-methylderhamnosylmaysin (3), apiferol (2) and alternanthin (8) which might be related to the antiadhesive activity of this subfraction against UPEC. Copyright © 2015 Elsevier B.V. All rights reserved.

Calcium isotopic anomalies and the lack of aluminum-26 in an unusual Allende inclusion

NASA Technical Reports Server (NTRS)

Lee, T.; Russell, W. A.; Wasserburg, G. J.

1979-01-01

This letter reports the discovery of an unusual Allende inclusion that is rich in hibonite, Ca(Al, Ti, Mg)12O19, the most refractory and possibly the most primitive major oxide mineral from the solar nebula. The Mg and Ca isotopic compositions of this hibonite-rich inclusion are studied in order to investigate the distribution of Al-26 in the solar system and to extend the search for isotopic anomalies. The Mg results indicate that no Mg isotopic anomalies are present, that the initial Al-26/Al-27 ratio for the inclusion when it crystallized was less than 200 billionths, and that the Mg mass-fractionation effect in the inclusion must be less than about 20 per mil/amu for the hibonite and 10 per mil/amu for other phases. The Ca studies reveal that large Ca mass-fractionation effects of about 7.5 per mil/amu are present and that additional small 'nonlinear' effects of presumably nuclear origin at a level of about 1 to 2 per mil are present in at least Ca-42. A plausible model for the evolution of the hibonite-rich inclusion is outlined.

Influence of high-pressure torsion on formation/destruction of nano-sized spinodal structures

NASA Astrophysics Data System (ADS)

Alhamidi, Ali; Edalati, Kaveh; Horita, Zenji

2018-04-01

The microstructures and hardness of Al - 30 mol.% Zn are investigated after processing by high-pressure torsion (HPT) for different numbers of revolutions, N = 1, 3, 10 or 25, as well as after post-HPT annealing at different temperatures, T = 373 K, 473 K, 573 K and 673 K. It was found that a work softening occurs by decreasing the grain size to the submicrometer level and increasing the fraction of high-angle boundaries. As a result of HPT processing, a complete decomposition of supersaturated solid solution of Zn in Al occurs and the spinodal structure is destroyed. This suggests that softening of the Al-Zn alloys after HPT is due to the decomposition of the supersaturated solid solution and destruction of spinodal decomposition. After post-HPT annealing, ultrafine-grained Al-Zn alloys show an unusual mechanical properties and its hardness increased to 187 HV. Microstructural analysis showed that the high hardness after post-HPT annealing is due to the formation of spinodal structures.

Fractional and hidden magnetic excitations in f-electron metal Yb2Pt2Pb

NASA Astrophysics Data System (ADS)

Zaliznyak, Igor

Quantum states with fractionalized excitations such as spinons in one-dimensional chains are commonly viewed as belonging to the domain of S=1/2 spin systems. However, recent experiments on the quantum antiferromagnet Yb2Pt2Pb, part of a large family of R2T2X (R=rare earth, T=transition metal, X=main group) materials spectacularly disqualify this opinion. The results show that spinons can also emerge in an f-electron system with strong spin-orbit coupling, where magnetism is mainly associated with large and anisotropic orbital moment. Here, the competition of several high-energy interactions Coulomb repulsion, spin-orbit coupling, crystal field, and the peculiar crystal structure, which combines low dimensionality and geometrical frustration, lead to the emergence, at low energy, of an effective spin-1/2, purely quantum Hamiltonian. Consequently, it produces unusual spin-liquid states and fractional excitations enabled by the inherently quantum mechanical nature of the moments. The emergent quantum spins bear the unique birthmark of their unusual origin in that they only lead to measurable longitudinal magnetic fluctuations, while the transverse excitations such as spin waves remain invisible to scattering experiments. Similarlyhidden would be transverse magnetic ordering, although it would have visible excitations. The rich magnetic phase diagram of Yb2Pt2Pb is suggestive of the existence of hidden-order phases, while the recent experiments indeed reveal the dark magnon, a hidden excitation in the saturated ferromagnetic (FM) phase of Yb2Pt2Pb. Unlike copper-based spin-1/2 chains, where the magnon in the FM state accounts for the full spectral weight of the zero-field spinon continuum, in the spin-orbital chains in Yb2Pt2Pb it is 100 times, or more weaker. It thus presents an example of dark magnon matter\\x9D, whose Hamiltonian is that of the effective spin-1/2 chain, but whose coupling to magnetic field, the physical probe at our disposal, is vanishingly small. The work was supported by the Office of Basic Energy Sciences, U.S. Department of Energy, under Contract No. DE-SC00112704, and by by NSF-DMR-1310008.

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.

Gap Reversal at Filling Factors 3 +1 /3 and 3 +1 /5 : Towards Novel Topological Order in the Fractional Quantum Hall Regime

NASA Astrophysics Data System (ADS)

Kleinbaum, Ethan; Kumar, Ashwani; Pfeiffer, L. N.; West, K. W.; Csáthy, G. A.

2015-02-01

In the region of the second Landau level several theories predict fractional quantum Hall states with novel topological order. We report the opening of an energy gap at the filling factor ν =3 +1 /3 , firmly establishing the ground state as a fractional quantum Hall state. This and other odd-denominator states unexpectedly break particle-hole symmetry. Specifically, we find that the relative magnitudes of the energy gaps of the ν =3 +1 /3 and 3 +1 /5 states from the upper spin branch are reversed when compared to the ν =2 +1 /3 and 2 +1 /5 counterpart states in the lower spin branch. Our findings raise the possibility that at least one of the former states is of an unusual topological order.

Environmental and genetic sources of diversification in the timing of seed germination: implications for the evolution of bet hedging.

PubMed

Simons, Andrew M; Johnston, Mark O

2006-11-01

Environmental variation that is not predictably related to cues is expected to drive the evolution of bet-hedging strategies. The high variance observed in the timing of seed germination has led to it being the most cited diversification strategy in the theoretical bet-hedging literature. Despite this theoretical focus, virtually nothing is known about the mechanisms responsible for the generation of individual-level diversification. Here we report analyses of sources of variation in timing of germination within seasons, germination fraction over two generations and three sequential seasons, and the genetic correlation structure of these traits using almost 10,000 seeds from more than 100 genotypes of the monocarpic perennial Lobelia inflata. Microenvironmental analysis of time to germination suggests that extreme sensitivity to environmental gradients, or microplasticity, even within a homogeneous growth chamber, may act as an effective individual-level diversification mechanism and explains more than 30% of variance in time to germination. The heritability of within-season timing of germination was low (h(2) = 0.07) but significant under homogeneous conditions. Consistent with individual-level diversification, this low h(2) was attributable not to low additive genetic variance, but to an unusually high coefficient of residual variation in time to germination. Despite high power to detect additive genetic variance in within-season diversification, it was low and indistinguishable from zero. Restricted maximum likelihood detected significant genetic variation for germination fraction (h(2) = 0.18) under homogeneous conditions. Unexpectedly, this heritability was positive when measured within a generation by sibling analysis and negative when measured across generations by offspring-on-parent regression. The consistency of dormancy fraction over multiple delays, a major premise of Cohen's classic model, was supported by a strong genetic correlation (r = 0.468) observed for a cohort's germination fraction over two seasons. We discuss implications of the results for the evolution of bet hedging and highlight the need for further empirical study of the causal components of diversification.

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...

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

ELLIPSOMETRY OF ELECTROCHEMICAL SURFACE LAYERS

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

Muller, R.H.

1977-06-01

Ellipsometry is concerned with the analysis and interpretation of changes in the state of polarization caused by reflection. The technique has found increasing interest in recent years for the measurement of thin films because it is unusually sensitive, disturbs the object minimally and can be applied to surfaces contained in any optically transparent medium. Film thicknesses amenable to measurement range from fractional monoatomic coverage to microscopic thicknesses. The measurement of changes in the state of polarization of light due to reflection provides an unusually sensitive tool for observing surface layers in any optically transparent environment. A fast, self-compensating ellipsometer hasmore » been used to observe the electrochemical formation of reacted surface layers. The optical effect of mass-transport boundary layers and component imperfections have been taken into account in the interpretation of results.« less

Timing Behavior of the Magnetically Active Rotation-Powered Pulsar in the Supernova Remnant Kesteven 75

NASA Technical Reports Server (NTRS)

Livingstone, Margaret A.; Gavriil, Fotis P.; Kaspi, Victoria M.

2009-01-01

We report a large spin-up glitch in PSR J1846-0258 which coincided with the onset of magnetar-like behavior on 2006 May 31. We show that the pulsar experienced an unusually large glitch recovery, with a recovery fraction of Q = 5.9+/-0.3, resulting in a net decrease of the pulse frequency. Such a glitch recovery has never before been observed in a rotation-powered pulsar, however, similar but smaller glitch over-recovery has been recently reported in the magnetar AXP 4U 0142+61 and may have occurred in the SGR 1900+14. We discuss the implications of the unusual timing behavior in PSR J1846-0258 on its status as the first identified magnetically active rotation-powered pulsar.

Fractional-exponent behavior of magnetization near Tc in Bi2Sr2CaCu2O8

NASA Astrophysics Data System (ADS)

Li, Lu; Naughton, M. J.; Ono, S.; Ong, N. P.

2005-03-01

Using high-resolution torque magnetometry, we have investigated in detail how long-range phase coherence develops as the critical temperature Tc (88.7 K) is approached in optimally-doped Bi2Sr2CaCuO8+δ with field H||c. Three distinct regimes are observed. Above ˜92 K, |M| increases rapidly as T->Tc in step with the vortex Nernst signal. M is strictly linear in H in weak H, but shows strong curvature at large H (5-14 T). The curvature provides a determination of the correlation length ξsc which grows as a power law, viz. ξsc˜1/t^ν. In the second regime, 86 < T < 92 K, M becomes nonlinear in H, viz. M˜H^α(T), where the exponent α(T) decreases from 1 to 0. This interesting fractional-exponent behavior is highly unusual and fits poorly with conventional pictures of `fluctuating diamagnetism.' As previously known, M is virtually H independent below 2 Tesla at the ``crossing temperature'' Tcr = 86 K. Below Tcr, M is a function of H. We compare this behavior with predictions of the 3DXY and Kosterlitz-Thouless theory. Supported by funds from the U.S. National Science Foundation under grant DMR 0213706.

Mesozooplankton biomass, composition, and potential grazing pressure on phytoplankton during austral winter and spring 1993 in the Subtropical Convergence region near New Zealand

NASA Astrophysics Data System (ADS)

Bradford-Grieve, Janet; Murdoch, Rob; James, Mark; Oliver, Megan; McLeod, Jeff

1998-10-01

The biomass, composition, and grazing rates of three size fractions of mesozooplankton (200-500, 500-1000, and some >1000 μm) were estimated in shelf waters and the water masses associated with Subtropical Convergence east of New Zealand, in the austral winter and spring of 1993, as part of a larger New Zealand study of ocean carbon flux that contributes to the Joint Global Ocean Flux Study (JGOFS). The total biomass was largest in spring in all water types. It was similar to the biomass measurements made previously in subantarctic and subtropical water masses in the Southwest Pacific and those from the North Atlantic, except for the spring biomass in subtropical water which was unusually large (86.5 and 101.3 mg m -3 dry weight). Biomass was concentrated in the upper 100 m, especially within the 0-25 or 25-50 m layers, both day and night. Night/day biomass ratios in the surface 100 m were often >2, and are presumed to be the result of sampling patchy populations as well as vertical migration. Biomass was greatest for the >1000 μm fraction of the mesozooplankton population, followed by the 500-1000, and 200-500 μm fractions, respectively. The unusually small fraction of biomass residing in the 200-500 μm fraction is assumed to be the result of predation by larger mesozooplankton. The mesozooplankton community had maximum gut fluorescence at night only at stations where chlorophyll a was >2 mg m -3 and at many of the stations gut fluorescence was persistently low. This was probably the result of the poor feeding environment, since a large proportion of the primary production resided in the <2 μm fraction. The total meaningestion of phytoplankton was calculated to be 1-40 mgC m -2 d -1, based mainly on ingestion by the 200-500 and 500-1000 μm fractions, which were dominated by herbivores or herbivores and omnivores. The heaviest grazing pressure was in subtropical and Subtropical Convergence waters, in spring. Total grazing represented <1-4% of daily total integrated primary production. Phytoplankton carbon ingested usually met only a small fraction of the basic metabolic requirements of the mesozooplankton. These data, and the fact that spring populations were apparently actively growing, since they contained a large proportion of developmental stages, imply that mesozooplankton diets were mainly microzooplankton.

Discovery of Emergent Photon and Monopoles in a Quantum Spin Liquid

NASA Astrophysics Data System (ADS)

Tokiwa, Yoshifumi; Yamashita, Takuya; Terazawa, Daiki; Kimura, Kenta; Kasahara, Yuichi; Onishi, Takafumi; Kato, Yasuyuki; Halim, Mario; Gegenwart, Philipp; Shibauchi, Takasada; Nakatsuji, Satoru; Moon, Eun-Gook; Matsuda, Yuji

2018-06-01

Quantum spin liquid (QSL) is an exotic quantum phase of matter whose ground state is quantum-mechanically entangled without any magnetic ordering. A central issue concerns emergent excitations that characterize QSLs, which are hypothetically associated with quasiparticle fractionalization and topological order. Here we report highly unusual heat conduction generated by the spin degrees of freedom in a QSL state of the pyrochlore magnet Pr2Zr2O7, which hosts spin-ice correlations with strong quantum fluctuations. The thermal conductivity in high temperature regime exhibits a two-gap behavior, which is consistent with the gapped excitations of magnetic (M-) and electric monopoles (E-particles). At very low temperatures below 200 mK, the thermal conductivity unexpectedly shows a dramatic enhancement, which well exceeds purely phononic conductivity, demonstrating the presence of highly mobile spin excitations. This new type of excitations can be attributed to emergent photons (ν-particle), coherent gapless spin excitations in a spin-ice manifold.

Adakite petrogenesis

NASA Astrophysics Data System (ADS)

Castillo, Paterno R.

2012-03-01

Adakite was originally proposed as a genetic term to define intermediate to high-silica, high Sr/Y and La/Yb volcanic and plutonic rocks derived from melting of the basaltic portion of oceanic crust subducted beneath volcanic arcs. It was also initially believed that adakite only occurs in convergent margins where young and, thus, still hot oceanic slabs are being subducted. Currently, adakite covers a range of arc rocks ranging from primary slab melt, to slab melt hybridized by peridotite, to melt derived from peridotite metasomatized by slab melt. Adakites can occur in arc settings where unusual tectonic conditions can lower the solidi of even older slabs and their source also includes subducted sediments. Results of adakite studies have generated controversies due to (1) the specific genetic definition of adakite but its reliance on trace element chemistry for its distinguishing characteristics, (2) curious association of adakite with alkalic rocks enriched in high field-strength elements and Cu-Au mineral deposits and (3) existence of adakitic rocks produced through other petrogenetic processes. Other studies have shown that adakitic rocks and a number of the previously reported adakites are produced through melting of the lower crust or ponded basaltic magma, high pressure crystal fractionation of basaltic magma and low pressure crystal fractionation of water-rich basaltic magma plus magma mixing processes in both arc or non-arc tectonic environments. Thus, although adakite investigations enrich our understanding of material recycling and magmatic processes along convergent margins, economic deposits and crustal evolutionary processes, the term adakite should be used with extreme caution.

Analysis of the ultrafine fraction of the Apollo 14 regolith

NASA Technical Reports Server (NTRS)

Finkelman, R. B.

1973-01-01

Analyses were obtained on more than 2400 randomly selected particles from the sub-37 micron (ultrafine) fraction of ten Apollo 14 regolith samples. The analyses were conducted with an energy dispersive electron microprobe system. The semiquantitative data were used to group the particles into ten categories. The pyroxene/plagioclase and olivine/plagioclase ratios are inconsistent with those ratios in the Apollo 14 breccias and rocks. The data suggest that fragmented basalts similar to Apollo 12 olivine basalts may have made significant contributions to the ultrafine fraction of the Fra Mauro regolith. Among a number of unusual particles encountered are brown, birefringent lath-shaped grains with 60 wt % SiO2 and 34 wt % FeO(FeSi2O5) and a glass with 20 to 25 wt % CaO, 0 to 8 wt % MgO, 40 to 45 wt % Al2O3 and approximately 30 wt % SiO2.

Orbital-exchange and fractional quantum number excitations in an f-electron metal Yb 2Pt 2Pb

DOE PAGES

L. S. Wu; Zaliznyak, I. A.; Gannon, W. J.; ...

2016-06-03

Exotic quantum states and fractionalized magnetic excitations, such as spinons in one-dimensional chains, are generally expected to occur in 3d transition metal systems with spin 1/2. Our neutron-scattering experiments on the 4f-electron metal Yb 2Pt 2Pb overturn this conventional wisdom. We observe broad magnetic continuum dispersing in only one direction, which indicates that the underlying elementary excitations are spinons carrying fractional spin-1/2. These spinons are the emergent quantum dynamics of the anisotropic, orbital-dominated Yb moments. Owing to their unusual origin, only longitudinal spin fluctuations are measurable, whereas the transverse excitations such as spin waves are virtually invisible to magnetic neutronmore » scattering. Furthermore, the proliferation of these orbital-spinons strips the electrons of their orbital identity, resulting in charge-orbital separation.« less

Two ways of legumin-precursor processing in conifers. Characterization and evolutionary relationships of Metasequoia cDNAs representing two divergent legumin gene subfamilies.

PubMed

Häger, K P; Wind, C

1997-06-15

Subunit monomers and oligomers of crystalloid-type legumins are major components of SDS-soluble fractions from Metasequoia glyptostroboides (Dawn redwood, Taxodiaceae) seed proteins. The subunits are made up of disulfide linked alpha-polypeptides and beta-polypeptides with molecular masses of 33 kDa and 23-25 kDa, respectively. Unusually for legumins, those from Metasequoia are glycosylated and the carbohydrate moieties are residing in the C-terminal region of the respective beta-polypeptides. A Metasequoia endosperm cDNA library has been constructed and legumin-encoding transcripts representing two divergent gene subfamilies have been characterized. Intersubfamily comparisons reveal 75% identity at the amino acid level and the values range from 53-35% when the legumin precursors deduced were compared with those from angiosperms. The predicted sequences together with data from amino acid sequencing prove that post-translational processing of Metasequoia prolegumins is directed to two different processing sites, each of them specific for one of the legumin subfamilies. The sites involved differ in their relative position and in the junction to be cleaved: Metasequoia legumin precursors MgLeg18 and MgLeg26 contain the conventional post-translational Asn-Gly processing site, which is generally regarded as highly conserved. In contrast, the MgLeg4 precursor is lacking this site and post-translational cleavage is directed to an unusual Asn-Thr processing site located in its hypervariable region, causing N-terminal extension of the beta-polypeptide relative to those hitherto known. Evidence is given that the unusual variant of processing also occurs in other conifers. Phylogenetic analysis reveals the precursors concerned as representatives of a distinct legumin subfamily, originating from duplication of an ancestral gene prior to or at the beginning of Taxodiaceae diversification.

Unusual 4-hydroxybenzaldehyde synthase activity from tissue cultures of the vanilla orchid Vanilla planifolia.

PubMed

Podstolski, Andrzej; Havkin-Frenkel, Daphna; Malinowski, Jacek; Blount, Jack W; Kourteva, Galina; Dixon, Richard A

2002-11-01

Tissue cultures of the vanilla orchid, Vanilla planifolia, produce the flavor compound vanillin (4-hydroxy-3-methoxybenzaldehyde) and vanillin precursors such as 4-hydroxybenzaldehyde. A constitutively expressed enzyme activity catalyzing chain shortening of a hydroxycinnamic acid, believed to be the first reaction specific for formation of vanilla flavor compounds, was identified in these cultures. The enzyme converts 4-coumaric acid non-oxidatively to 4-hydroxybenzaldehyde in the presence of a thiol reagent but with no co-factor requirement. Several forms of this 4-hydroxybenzaldehyde synthase (4HBS) were resolved and partially purified by a combination of hydrophobic interaction, ion exchange and gel filtration chromatography. These forms appear to be interconvertible. The unusual properties of the 4HBS, and its appearance in different protein fractions, raise questions as to its physiological role in vanillin biosynthesis in vivo.

Unusual structures in the polysaccharides from the red seaweed Pterocladiella capillacea (Gelidiaceae, Gelidiales).

PubMed

Errea, María I; Matulewicz, María C

2003-04-22

Sequential extraction of tetrasporic Pterocladiella capillacea with water at room temperature and then at 50 degrees C led to the isolation of two products that were each fractionated with cetrimide to give a soluble fraction and a precipitate. The precipitates were then subjected to fractional solubilization in solutions of increasing sodium chloride concentration. The whole treatment yielded two major fractions in each case, one soluble in the cetrimide medium and the other soluble in 0.5 M NaCl, which were further fractionated by anion-exchange chromatography. Structural analysis, carried out by methylation, desulfation-methylation, 13C NMR spectroscopy and determination of the absolute configuration of the 2,6-di-O-methylgalactose units in the permethylated products, indicated the presence of xylogalactans, with low content of 3,6-anhydrogalactose and low molecular weight. These polysaccharides varied in the level of xylopyranosyl and sulfate substitution, primarily on the 6-position of the 3-linked beta-D-galactopyranosyl and on the 3-position of the 4-linked alpha-galactopyranosyl units. Moreover, herein we report, for the first time, the presence of 3-substituted, 4-linked D-galactopyranosyl residues in an alga belonging to the Gelidiales.

HOT-DUST-POOR TYPE 1 ACTIVE GALACTIC NUCLEI IN THE COSMOS SURVEY

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

Hao Heng; Elvis, Martin; Civano, Francesca

2010-11-20

We report a sizable class of type 1 active galactic nuclei (AGNs) with unusually weak near-infrared (1-3 {mu}m) emission in the XMM-COSMOS type 1 AGN sample. The fraction of these 'hot-dust-poor' AGNs increases with redshift from 6% at low redshift (z < 2) to 20% at moderate high redshift (2 < z < 3.5). There is no clear trend of the fraction with other parameters: bolometric luminosity, Eddington ratio, black hole mass, and X-ray luminosity. The 3 {mu}m emission relative to the 1 {mu}m emission is a factor of 2-4 smaller than the typical Elvis et al. AGN spectral energymore » distribution (SED), which indicates a 'torus' covering factor of 2%-29%, a factor of 3-40 smaller than required by unified models. The weak hot dust emission seems to expose an extension of the accretion disk continuum in some of the source SEDs. We estimate the outer edge of their accretion disks to lie at (0.3-2.0) x 10{sup 4} Schwarzschild radii, {approx}10-23 times the gravitational stability radii. Formation scenarios for these sources are discussed.« less

Co-solvent pretreatment reduces costly enzyme requirements for high sugar and ethanol yields from lignocellulosic biomass.

PubMed

Nguyen, Thanh Yen; Cai, Charles M; Kumar, Rajeev; Wyman, Charles E

2015-05-22

We introduce a new pretreatment called co-solvent-enhanced lignocellulosic fractionation (CELF) to reduce enzyme costs dramatically for high sugar yields from hemicellulose and cellulose, which is essential for the low-cost conversion of biomass to fuels. CELF employs THF miscible with aqueous dilute acid to obtain up to 95 % theoretical yield of glucose, xylose, and arabinose from corn stover even if coupled with enzymatic hydrolysis at only 2 mgenzyme  gglucan (-1) . The unusually high saccharification with such low enzyme loadings can be attributed to a very high lignin removal, which is supported by compositional analysis, fractal kinetic modeling, and SEM imaging. Subsequently, nearly pure lignin product can be precipitated by the evaporation of volatile THF for recovery and recycling. Simultaneous saccharification and fermentation of CELF-pretreated solids with low enzyme loadings and Saccharomyces cerevisiae produced twice as much ethanol as that from dilute-acid-pretreated solids if both were optimized for corn stover. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Unusual presentation of pheochromocytoma with ischemic sigmoid colitis and stenosis.

PubMed

Tan, Florence; Thai, Ah Chuan; Cheah, Wei Keat; Mukherjee, J J

2009-10-01

A 45-year-old woman with poorly controlled hypertension and diabetes mellitus presented with left iliac fossa pain, constipation alternating with diarrhea, and weight loss. She had been diagnosed with idiopathic cardiomyopathy five years previously. Echocardiogram had shown a left ventricular ejection fraction (LVEF) of 35%; coronary angiogram was normal. Colonoscopy revealed sigmoid colitis with stenosis. Abdominal computed tomography revealed a 5 cm right adrenal tumor. Twenty-four hour urinary free catecholamines and fractionated metanephrine excretion values were elevated, confirming pheochromocytoma. Her colitis resolved after one month of adrenergic blockade. Repeat echocardiogram showed improvement of LVEF to 65%. After laparoscopic right adrenalectomy, the patient's hypertension resolved, and diabetic control improved. Timely management avoided further morbidity and potential mortality in our patient.

Successful Treatment of Tattoo-Induced Pseudolymphoma with Sequential Ablative Fractional Resurfacing Followed by Q-Switched Nd: YAG 532 nm Laser

PubMed Central

Lucinda, Tan Siyun; Hazel, Oon Hwee Boon; Joyce, Lee Siong Siong; Hon, Chua Sze

2013-01-01

Decorative tattooing has been linked with a range of complications, with pseudolymphoma being unusual and challenging to manage. We report a case of tattoo-induced pseudolymphoma, who failed treatment with potent topical and intralesional steroids. She responded well to sequential treatment with ablative fractional resurfacing (AFR) followed by Q-Switched (QS) Nd:YAG 532 nm laser. Interestingly, we managed to document the clearance of her tattoo pigments after laser treatments on histology and would like to highlight the use of special stains such as the Grocott's Methenamine Silver (GMS) stain as a useful method to assess the presence of tattoo pigment in cases where dense inflammatory infiltrates are present. PMID:24470721

Cholesterol removal from adult skeletal muscle impairs excitation–contraction coupling and aging reduces caveolin-3 and alters the expression of other triadic proteins

PubMed Central

Barrientos, Genaro; Llanos, Paola; Hidalgo, Jorge; Bolaños, Pura; Caputo, Carlo; Riquelme, Alexander; Sánchez, Gina; Quest, Andrew F. G.; Hidalgo, Cecilia

2015-01-01

Cholesterol and caveolin are integral membrane components that modulate the function/location of many cellular proteins. Skeletal muscle fibers, which have unusually high cholesterol levels in transverse tubules, express the caveolin-3 isoform but its association with transverse tubules remains contentious. Cholesterol removal impairs excitation–contraction (E–C) coupling in amphibian and mammalian fetal skeletal muscle fibers. Here, we show that treating single muscle fibers from adult mice with the cholesterol removing agent methyl-β-cyclodextrin decreased fiber cholesterol by 26%, altered the location pattern of caveolin-3 and of the voltage dependent calcium channel Cav1.1, and suppressed or reduced electrically evoked Ca2+ transients without affecting membrane integrity or causing sarcoplasmic reticulum (SR) calcium depletion. We found that transverse tubules from adult muscle and triad fractions that contain ~10% attached transverse tubules, but not SR membranes, contained caveolin-3 and Cav1.1; both proteins partitioned into detergent-resistant membrane fractions highly enriched in cholesterol. Aging entails significant deterioration of skeletal muscle function. We found that triad fractions from aged rats had similar cholesterol and RyR1 protein levels compared to triads from young rats, but had lower caveolin-3 and glyceraldehyde 3-phosphate dehydrogenase and increased Na+/K+-ATPase protein levels. Both triad fractions had comparable NADPH oxidase (NOX) activity and protein content of NOX2 subunits (p47phox and gp91phox), implying that NOX activity does not increase during aging. These findings show that partial cholesterol removal impairs E–C coupling and alters caveolin-3 and Cav1.1 location pattern, and that aging reduces caveolin-3 protein content and modifies the expression of other triadic proteins. We discuss the possible implications of these findings for skeletal muscle function in young and aged animals. PMID:25914646

200 million years of komatiite evolution in the Barberton Greenstone Belt, South Africa

NASA Astrophysics Data System (ADS)

Christoph, Robin; Arndt, Nick; Byerly, Gary; Puchtel, Igor; Blichert-Toft, Janne; Wilson, Allan

2010-05-01

Komatiites with complex and contrasting chemical compositions erupted throughout the 200 m.y. history of the Barberton greenstone belt in South Africa. The oldest well-preserved examples, from the ca. 3.5 Ga Komati Formation, display a range of volcanic structures, from thin differentiated spinifex-textured flows to much thicker flows or sills composed mainly of massive olivine cumulate. Pyroxene spinifex layers that cap the latter units indicate crystallization from komatiitic basaltic liquids. Although some rare, unusually coarse, vesicular, completely serpentinized units may have contained a small fraction of water, most of the flows are essentially anhydrous. Two geochemical types are present in the Komati Fm; Al-depleted komatiites with moderately enriched LREE and depleted HREE, and Al-undepleted komatiites with near-chondritic REE ratios. Komatiites from the 3.2 Ga Mendon and Weltevreden Fm display two patterns -Al-undepleted with near-chondritic REE ratios and Al-enriched with extremely low REE concentrations and marked depletion of LREE. In many units, both geochemical types are present. The Al- and HREE-depletion of Komati Fm magmas indicates that residual garnet was retained in the mantle source and their high MgO contents require that melting was at great depth. Up to 30% batch melting at 300 km depth is indicated; the high percentage of batch melting is possible because melt is neutrally buoyant at these depths. The Al-undepleted to enrichedmagmas formed by up to 50% cumulative fractional melting that terminated at shallower depth. The. presence of both types inseveral units points to complex dynamics in the mantle plumes that yielded these magmas. Epsilon Nd in all Barbertonkomatiites ranges from 0 to +2; epsilon Hf from +2 to +7; gamma Os from 0 to +3.7. The combination of fractionated REE, positive epsilon Nd and Hf, and near-chondritic Os in certain komatiites is attributed to differentiation of the komatiite sourcevery early in Earth history followed by fractionation during komatiite formation.

Particle size distribution of distillers dried grains with solubles (DDGS) and relationships to compositional and color properties.

PubMed

Liu, Keshun

2008-11-01

Eleven distillers dried grains with solubles (DDGS), processed from yellow corn, were collected from different ethanol processing plants in the US Midwest area. Particle size distribution (PSD) by mass of each sample was determined using a series of six selected US standard sieves: Nos. 8, 12, 18, 35, 60, and 100, and a pan. The original sample and sieve sized fractions were measured for surface color and contents of moisture, protein, oil, ash, and starch. Total carbohydrate (CHO) and total non-starch CHO were also calculated. Results show that there was a great variation in composition and color among DDGS from different plants. Surprisingly, a few DDGS samples contained unusually high amounts of residual starch (11.1-17.6%, dry matter basis, vs. about 5% of the rest), presumably resulting from modified processing methods. Particle size of DDGS varied greatly within a sample and PSD varied greatly among samples. The 11 samples had a mean value of 0.660mm for the geometric mean diameter (dgw) of particles and a mean value of 0.440mm for the geometric standard deviation (Sgw) of particle diameters by mass. The majority had a unimodal PSD, with a mode in the size class between 0.5 and 1.0mm. Although PSD and color parameters had little correlation with composition of whole DDGS samples, distribution of nutrients as well as color attributes correlated well with PSD. In sieved fractions, protein content, L and a color values negatively while contents of oil and total CHO positively correlated with particle size. It is highly feasible to fractionate DDGS for compositional enrichment based on particle size, while the extent of PSD can serve as an index for potential of DDGS fractionation. The above information should be a vital addition to quality and baseline data of DDGS.

Compositional and stable carbon isotopic fractionation during non-autocatalytic thermochemical sulfate reduction by gaseous hydrocarbons

USGS Publications Warehouse

Xia, Xinyu; Ellis, Geoffrey S.; Ma, Qisheng; Tang, Yongchun

2014-01-01

The possibility of autocatalysis during thermochemical sulfate reduction (TSR) by gaseous hydrocarbons was investigated by examination of previously reported laboratory and field data. This reaction was found to be a kinetically controlled non-autocatalytic process, and the apparent lack of autocatalysis is thought to be due to the absence of the required intermediate species. Kinetic parameters for chemical and carbon isotopic fractionations of gaseous hydrocarbons affected by TSR were calculated and found to be consistent with experimentally derived values for TSR involving long-chain hydrocarbons. Model predictions based on these kinetic values indicate that TSR by gaseous hydrocarbon requires high-temperature conditions. The oxidation of C2–5 hydrocarbons by sulfate reduction is accompanied by carbon isotopic fractionation with the residual C2–5 hydrocarbons becoming more enriched in 13C. Kinetic parameters were calculated for the stable carbon isotopic fractionation of gaseous hydrocarbons that have experienced TSR. Model predictions based on these kinetics indicate that it may be difficult to distinguish the effects of TSR from those of thermal maturation at lower levels of hydrocarbon oxidation; however, unusually heavy δ13C2+ values (>−10‰) can be diagnostic of high levels of conversion (>50%). Stoichiometric and stable carbon isotopic data show that methane is stable under the investigated reaction conditions and is likely a product of TSR by other gaseous hydrocarbons rather than a significant reactant. These results indicate that the overall TSR reaction mechanism for oxidation of organic substrates containing long-chain hydrocarbons involves three distinct phases as follows: (1) an initial slow and non-autocatalytic stage characterized by the reduction of reactive sulfate by long-chain saturated hydrocarbons; (2) a second autocatalytic reaction phase dominated by reactions involving reduced sulfur species and partially oxidized hydrocarbons; (3) and a final, or late-stage, TSR reaction in which hydrocarbon oxidation continues at a slower rate via the non-autocatalytic reduction of sulfate by gaseous hydrocarbons.

High-resolution extreme ultraviolet spectroscopy of G191-B2B: structure of the stellar photosphere and the surrounding interstellar medium

NASA Astrophysics Data System (ADS)

Barstow, M. A.; Cruddace, R. G.; Kowalski, M. P.; Bannister, N. P.; Yentis, D.; Lapington, J. S.; Tandy, J. A.; Hubeny, I.; Schuh, S.; Dreizler, S.; Barbee, T. W.

2005-10-01

We have continued our detailed analysis of the high-resolution (R= 4000) spectroscopic observation of the DA white dwarf G191-B2B, obtained by the Joint Astrophysical Plasmadynamic Experiment (J-PEX) normal incidence sounding rocket-borne telescope, comparing the observed data with theoretical predictions for both homogeneous and stratified atmosphere structures. We find that the former models give the best agreement over the narrow waveband covered by J-PEX, in conflict with what is expected from previous studies of the lower resolution but broader wavelength coverage Extreme Ultraviolet Explorer spectra. We discuss the possible limitations of the atomic data and our understanding of the stellar atmospheres that might give rise to this inconsistency. In our earlier study, we obtained an unusually high ionization fraction for the ionized HeII present along the line of sight to the star. In the present paper, we obtain a better fit when we assume, as suggested by Space Telescope Imaging Spectrograph results, that this HeII resides in two separate components. When one of these is assigned to the local interstellar cloud, the implied He ionization fraction is consistent with measurements along other lines of sight. However, the resolving power and signal-to-noise available from the instrument configuration used in this first successful J-PEX flight are not sufficient to clearly identify and prove the existence of the two components.

Affinity purification of the voltage-sensitive sodium channel from electroplax with resins selective for sialic acid

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

James, W.M.; Emerick, M.C.; Agnew, W.S.

1989-07-11

The voltage-sensitive sodium channel present in the eel (Electrophorus electricus) has an unusually high content of sialic acid, including {alpha}-(2{yields}8)-linked polysialic acid, not found in other electroplax membrane glycopeptides. Lectins from Limax flavus (LFA) and wheat germ (WGA) proved the most effective of 11 lectin resins tried. The most selective resin was prepared from IgM antibodies against Neisseria meningitidis {alpha}-(2{yields}8)-polysialic acid which were affinity purified and coupled to Sepharose 4B. The sodium channel was found to bind to WGA, LFA, and IgM resins and was readily eluted with the appropriate soluble carbohydrates. Experiments with LFA and IgM resins demonstrated bindingmore » and unbinding rates and displacement kinetics, which suggest highly specific binding at multiple sites on the sodium channel protein. In preparative-scale purification of protein previously fractionated by anion-exchange chromatography, without stabilizing TTX, high yields were reproducibly obtained. Further, when detergent extracts were prepared from electroplax membranes fractionated by low-speed sedimentation, a single step over the IgM resin provided a 70-fold purification, yielding specific activities of 3,200 pmol of ({sup 3}H)TTX-binding sites/mg of protein and a single polypeptide of {approximately}285,000 Da on SDS-acrylamide gels. No small peptides were observed after this 5-h isolation. The authors describe a cation-dependent stabilization with millimolar levels of monovalent and micromolar levels of divalent species.« less

Thondhjemite of the Talkeetna Mountains: An unusually large low-K pluton in Alaska's Peninsular terrane

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

Ford, A.B.; Arth, J.G.; Csejtey, B.

1993-04-01

An unusually large, elongate Jurassic pluton of trondhjemite, about 120- by 10--15 km in dimensions, intruded Jurassic plutonic and metamorphic rocks of the Peninsular terrane in the central Talkeetna Mountains of south-central Alaska. Muscovite and biotite yield minimum ages of 150--145 Ma. The N40[degree]E-trending body is concordant with regional structures. It is the youngest member of a subduction-related Jurassic plutonic suite in the Peninsular terrane that, along with Wrangellia, was accreted to the North American continent in the middle Cretaceous. Rocks, commonly sheared, are medium to coarse grained and leucocratic (CI = 3--9). Biotite is the chief mafic mineral. Minormore » muscovite and garnet are common and green hornblende rare. Samples (n = 27) from the body's entire length have an average Mg[number sign] of 45 and an SiO[sub 2] continuum of 67--74% (avg. 70.7%). High Al[sub 2]O[sub 3] (14.4--17.9%, avg. 16.5%) is typical of continental trondhjemite. Averages for Zr (109 ppm) and Nb (3.5 ppm) and the ratios K/Rb (491) and Zr/Nb (34) are typical of orogenic igneous rocks of subduction origin. Four samples analyzed have low ([sup 87]Sr/[sup 86]Sr)[sub i] (avg. 0.7036). Very low Rb/Sr (avg. 0.027) is similar to Idaho batholith trondhjemites. REE patterns with low to moderate LREE and HREE with flat patterns and low contents suggest residual garnet or hornblende during partial melting or fractionation. The pluton appears homogeneous in outcrop. However, some geographic variations in chemistry, as in SiO[sub 2] contents and especially in Eu/Eu[sup *], suggest existence of perhaps three regionally separate plumbing systems, or chambers in which different processes such as plagioclase accumulation or hornblende fractionation were active.« less

Sign Crossover in All Maxwell-Stefan Diffusivities for Molten Salt LiF-BeF2: A Molecular Dynamics Study.

PubMed

Chakraborty, Brahmananda

2015-08-20

Applying Green-Kubo formalism and equilibrium molecular dynamics (MD) simulations, we have studied for the first time the dynamic correlation, Onsager coefficients, and Maxwell-Stefan (MS) diffusivities of molten salt LiF-BeF2, which is a potential candidate for a coolant in a high temperature reactor. We observe an unusual composition dependence and strikingly a crossover in sign for all the MS diffusivities at a composition of around 7% of LiF where the MS diffusivity between cation-anion pair (Đ(BeF) and Đ(LiF)) jumps from positive to negative value while the MS diffusivity between cation-cation pair (Đ(LiBe)) becomes positive from a negative value. Even though the negative MS diffusivities have been observed for electrolyte solutions between cation-cation pair, here we report negative MS diffusivity between cation-anion pair where Đ(BeF) shows a sharp rise around 66% of BeF2, reaches maximum value at 70% of BeF2, and then decreases almost exponentially with a sign change for BeF2 around 93%. For low mole fraction of LiF, Đ(BeF) follows the Debye-Huckel theory and rises with the square root of LiF mole fraction similar to the MS diffusivity between cation-anion pair in aqueous solution of electrolyte salt. Negative MS diffusivities while unusual are, however, shown to satisfy the non-negative entropy constraints at all thermodynamic states as required by the second law of thermodynamics. We have established a strong correlation between the structure and dynamics and predict that the formation of flouride polyanion network between Be and F ions and coulomb interaction is responsible for sharp variation of the MS diffusivities which controls the multicomponent diffusion phenomenon in LiF-BeF2 which has a strong impact on the performance of the reactor.

Immunoglobulins in bovine mammary secretions

PubMed Central

Porter, P.

1972-01-01

Antibodies against Escherichia coli 08 in bovine colostrum and serum have been studied by gel filtration chromatography and the red cell linked antigen—antiglobulin reaction. Immunoglobulins were assayed by radial immunodiffusion. In bovine colostrum anti-E. coli activity was attributable to IgA and the level of activity was comparable with that detected in IgM and IgG fractions. The immunoglobulin profile and distribution of E. coli antibodies in post-colostral calf serum was similar to that in colostrum, thus providing an unusual occurrence of high levels of secretory IgA in serum. However the immunoglobulin disappeared rapidly from the serum with an apparent half life of approximately 2 days; the value for IgM was 4 days. During the first 3 days of lactation the levels of immunoglobulins fall rapidly and milk is subsequently secreted with uniformly low levels of antibodies. PMID:4560742

Investigation of cavitating flows by X-ray and optical imaging

NASA Astrophysics Data System (ADS)

Coutier-Delgosha, Olivier; Fuzier, Sylvie; Khlifa, Ilyass; Fezzaa, Kamel

2015-11-01

Hydrodynamic cavitation is the partial vaporization of high speed liquid flows. The turbulent, compressible and unsteady character of these flows makes their study unusually complex and challenging. Instabilities generated by the occurrence of cavitation have been investigated in the last years in the LML laboratory by various non-intrusive measurements including X-ray imaging (to obtain the fields of void fraction and velocity in both phases), and PIV with fluorescent particles (to obtain the velocity fields in both phases). It has been shown that cavitation is characterized by significant slip velocities between liquid and vapor, especially in the re-entrant jet area and the cavity wake. This results suggests some possible improvements in the numerical models currently used for CFD of cavitating flows. Professor at Arts et Metiers ParisTech, Director of the LML laboratory.

[Unusual aspect of pernicious anemia during association of beta-thalassemia: a new case report and literature review].

PubMed

Diop, Madoky Magatte; Toure, P S; Leye, M Y; Leye, A; El Fadjri, S; Diop, M; Ka, M M; Diop, Oulimata D; Fall, S; Ndiaye, F S

2012-01-01

Pernicious anemia appears classically by macrocytosis. We report a case of a late discovered Biermer disease, on a 42-year-old young black woman. The reason was an unusual aspect of this disease in a context of betathalassemia. The patient presented chronic anemia which evolved during about ten year. Biology showed a normocytosis and signs of hemolysis according to beta-thalassemia. This was confirmed by an electrophoresis showing 9.1 % of fraction F some haemoglobin. Since this date, the patient was treated by folic acid alone with periodic transfusions of red blood cell. She presented eight years after the beginning of her disease, neurological deterioration. Diagnosis of pernicious anemia was finally established up on histological gastritis, low level of the blood rate of vitamin B12, macrocytosis, and presence of intrinsic anti-factor and parietal anti-cells antibodies.

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 other prey-capture silk: Fibres made by glow-worms (Diptera: Keroplatidae) comprise cross-β-sheet crystallites in an abundant amorphous fraction.

PubMed

Walker, Andrew A; Weisman, Sarah; Trueman, Holly E; Merritt, David J; Sutherland, Tara D

2015-09-01

Glow-worms (larvae of dipteran genus Arachnocampa) are restricted to moist habitats where they capture flying prey using snares composed of highly extensible silk fibres and sticky mucus droplets. Little is known about the composition or structure of glow-worm snares, or the extent of possible convergence between glow-worm and arachnid capture silks. We characterised Arachnocampa richardsae silk and mucus using X-ray scattering, Fourier transform infrared spectroscopy and amino acid analysis. Silk but not mucus contained crystallites of the cross-β-sheet type, which occur in unrelated insect silks but have not been reported previously in fibres used for prey capture. Mucus proteins were rich in Gly (28.5%) and existed in predominantly a random coil structure, typical of many adhesive proteins. In contrast, the silk fibres were unusually rich in charged and polar residues, particularly Lys (18.1%), which we propose is related to their use in a highly hydrated state. Comparison of X-ray scattering, infrared spectroscopy and amino acid analysis data suggests that silk fibres contain a high fraction of disordered protein. We suggest that in the native hydrated state, silk fibres are capable of extension via deformation of both disordered regions and cross-β-sheet crystallites, and that high extensibility is an adaptation promoting successful prey capture. This study illustrates the rich variety of protein motifs that are available for recruitment into biopolymers, and how convergently evolved materials can nevertheless be based on fundamentally different protein structures. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Robust spin correlations at high magnetic fields in the harmonic honeycomb iridates

DOE PAGES

Modic, K. A.; Ramshaw, Brad J.; Betts, J. B.; ...

2017-08-01

Here, the complex antiferromagnetic orders observed in the honeycomb iridates are a double-edged sword in the search for a quantum spin-liquid: both attesting that the magnetic interactions provide many of the necessary ingredients, while simultaneously impeding access. Focus has naturally been drawn to the unusual magnetic orders that hint at the underlying spin correlations. However, the study of any particular broken symmetry state generally provides little clue about the possibility of other nearby ground states. Here we use magnetic fields approaching 100 Tesla to reveal the extent of the spin correlations in γ-lithium iridate. We find that a small componentmore » of field along the magnetic easy-axis melts long-range order, revealing a bistable, strongly correlated spin state. Far from the usual destruction of antiferromagnetism via spin polarization, the high-field state possesses only a small fraction of the total iridium moment, without evidence for long-range order up to the highest attainable magnetic fields.« less

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

Sechium edule (Jacq.) Swartz, a New Cultivar with Antiproliferative Potential in a Human Cervical Cancer HeLa Cell Line.

PubMed

Salazar-Aguilar, Sandra; Ruiz-Posadas, Lucero Del Mar; Cadena-Iñiguez, Jorge; Soto-Hernández, Marcos; Santiago-Osorio, Edelmiro; Aguiñiga-Sánchez, Itzen; Rivera-Martínez, Ana Rocío; Aguirre-Medina, Juan Francisco

2017-07-25

The Sechium edule Perla Negra cultivar is a recently-obtained biological material whose progenitors are S. edule var. nigrum minor and S. edule var. amarus silvestrys, the latter of which has been reported to have antiproliferative activity against the HeLa P-388 and L-929 cancer cell lines. The present study aimed to determine if the methanolic extract of the fruit of the Perla Negra cultivar had the same biological activity. The methanolic extract was phytochemically characterized by thin layer chromatography (TLC) and column chromatography (CC), identifying the terpenes and flavonoids. The compounds identified via high performance liquid chromatography (HPLC) were Cucurbitacins B, D, E, and I for the terpene fractions, and Rutin, Phlorizidin, Myricetin, Quercetin, Naringenin, Phloretin, Apigenin, and Galangin for the flavonoid fractions). Biological activity was evaluated with different concentrations of the methanolic extract in the HeLa cell line and normal lymphocytes. The methanolic extract inhibited the proliferation of HeLa cells (IC 50 1.85 µg·mL -1 ), but the lymphocytes were affected by the extract (IC 50 30.04 µg·mL -1 ). Some fractions, and the pool of all of them, showed inhibition higher than 80% at a concentration of 2.11 µg·mL -1 . Therefore, the biological effect shown by the methanolic extract of the Perla Negra has some specificity in inhibiting tumor cells and not normal cells; an unusual feature among molecules investigated as potential biomedical agents.

Sechium edule (Jacq.) Swartz, a New Cultivar with Antiproliferative Potential in a Human Cervical Cancer HeLa Cell Line

PubMed Central

Salazar-Aguilar, Sandra; Ruiz-Posadas, Lucero del Mar; Cadena-Iñiguez, Jorge; Santiago-Osorio, Edelmiro; Aguiñiga-Sánchez, Itzen; Rivera-Martínez, Ana Rocío; Aguirre-Medina, Juan Francisco

2017-01-01

The Sechium edule Perla Negra cultivar is a recently-obtained biological material whose progenitors are S. edule var. nigrum minor and S. edule var. amarus silvestrys, the latter of which has been reported to have antiproliferative activity against the HeLa P-388 and L-929 cancer cell lines. The present study aimed to determine if the methanolic extract of the fruit of the Perla Negra cultivar had the same biological activity. The methanolic extract was phytochemically characterized by thin layer chromatography (TLC) and column chromatography (CC), identifying the terpenes and flavonoids. The compounds identified via high performance liquid chromatography (HPLC) were Cucurbitacins B, D, E, and I for the terpene fractions, and Rutin, Phlorizidin, Myricetin, Quercetin, Naringenin, Phloretin, Apigenin, and Galangin for the flavonoid fractions). Biological activity was evaluated with different concentrations of the methanolic extract in the HeLa cell line and normal lymphocytes. The methanolic extract inhibited the proliferation of HeLa cells (IC50 1.85 µg·mL−1), but the lymphocytes were affected by the extract (IC50 30.04 µg·mL−1). Some fractions, and the pool of all of them, showed inhibition higher than 80% at a concentration of 2.11 µg·mL−1. Therefore, the biological effect shown by the methanolic extract of the Perla Negra has some specificity in inhibiting tumor cells and not normal cells; an unusual feature among molecules investigated as potential biomedical agents. PMID:28757593

Tracing Pleistocene to Holocene meltwater events and provenance of sediments in Baffin Bay using radiogenic isotope signals

NASA Astrophysics Data System (ADS)

Kirillova, Valeriia; Kasemann, Simone A.; Lucassen, Friedrich

2016-04-01

Large meltwater discharge is the principal carrier of detritus from the continent into the ocean and the dispersion of this detritus by ocean currents is a measure for the spatially focused addition of freshwater in the ocean in the high latitude areas. To trace Greenland ice sheet dynamics and freshwater routing during late Pleistocene to Holocene climate transition, we generate strontium (Sr), neodymium (Nd) and lead (Pb) isotope records on sediment cores in the Baffin Bay: GeoTÜ SL 170, covering the last 18.000 years of climate history and GeoTÜ SL 174, covering 40.000 years. Sr, Nd and Pb isotopes are used as proxies for the provenance of continental detritus and seawater sources. Isotope analyses were performed on two separated fractions from the sedimentary core material: the chemically leached fraction and the remaining detritus. Leachates are supposed to represent Fe-Mn coatings formed on the surface of the sediment grains and to reflect the bottom water signal. The detrital fraction acts as a tracer for the meltwater event and weathering regime of the nearby continental masses. For the detrital fraction of the core SL 170, a pronounced shift can be observed in all three isotope systems at ˜ 12 ka, what coincides with the Younger Dryas cold event. For the detrital fraction the 87Sr/86Sr is around ˜0,72 before the event and reaches up to ˜0,74 after. Nd isotope composition (ɛNd) changed from ˜-26 to ˜-32. The shift suggests a change in the continental sources from West and West-South Greenland to the Baffin Island and Canadian Archipelago. It can be explained by the ice sheet melting processes. The 206Pb/204Pb values for the detrital fraction range from ˜17 before the shift to ˜18 after. On the contrary, the leachates show pronounced radiogenic signatures with values changing from ˜21 to ˜23. The reason for such an unusual high values is most likely in the composition of the leached material, which doesn't seem to show the presence of Fe-Mn coatings as was suggested before. The work on the second core SL 174 is in progress. Up to now the results show similar patterns for isotope ratios as in the case of SL 170.

Iron-mineral accretion from acid mine drainage and its application in passive treatment

PubMed Central

Florence, K.; Sapsford, D.J.; Johnson, D.B.; Kay, C.M.; Wolkersdorfer, C.

2016-01-01

ABSTRACT This study demonstrates substantial removal of iron (Fe) from acid mine drainage (pH ≈3) in a passive vertical flow reactor (VFR) with an equivalent footprint of 154 m2 per L/s mine water and residence times of >23 h. Average Fe removal rate was 67% with a high of 85% over the 10-month trial. The fraction of Fe passing a 0.22 µm filter (referred to here as Fe-filt) was seen to be removed in the VFR even when Fe(II) was absent, indicating that the contribution of microbial Fe(II) oxidation and precipitation was not the dominant removal mechanism in the VFR. Removal rates of Fe-filt in the VFR were up to 70% in residence times as low as 8 h compared with laboratory experiments where much smaller changes in Fe-filt were observed over 60 h. Centrifugation indicated that 80–90% of the influent Fe had particle sizes <35 nm. Together with analyses and geochemical modelling, this suggests that the Fe-filt fraction exists as either truly aqueous (but oversaturated) Fe(III) or nanoparticulate Fe(III) and that this metastability persists. When the water was contacted with VFR sludge, the Fe-filt fraction was destabilized, leading to an appreciably higher removal of this fraction. Heterogeneous precipitation and/or aggregation of nanoparticulate Fe(III) precipitates are considered predominant removal mechanisms. Microbial analyses of the mine water revealed the abundance of extracellular polymeric substance-generating Fe-oxidizing bacterium ‘Ferrovum myxofaciens’, which may aid the removal of iron and explain the unusual appearance and physical properties of the sludge. PMID:26675674

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

Physics of the Kitaev Model: Fractionalization, Dynamic Correlations, and Material Connections

NASA Astrophysics Data System (ADS)

Hermanns, M.; Kimchi, I.; Knolle, J.

2018-03-01

Quantum spin liquids have fascinated condensed matter physicists for decades because of their unusual properties such as spin fractionalization and long-range entanglement. Unlike conventional symmetry breaking, the topological order underlying quantum spin liquids is hard to detect experimentally. Even theoretical models are scarce for which the ground state is established to be a quantum spin liquid. The Kitaev honeycomb model and its generalizations to other tricoordinated lattices are chief counterexamples - they are exactly solvable, harbor a variety of quantum spin liquid phases, and are also relevant for certain transition metal compounds including the polymorphs of (Na,Li)2IrO3 iridates and RuCl3. In this review, we give an overview of the rich physics of the Kitaev model, including two-dimensional and three-dimensional fractionalization as well as dynamic correlations and behavior at finite temperatures. We discuss the different materials and argue how the Kitaev model physics can be relevant even though most materials show magnetic ordering at low temperatures.

Magnesium and Titanium Isotopic Compositions of an Unusual Hibonite-Perovskite Refractory Inclusion from Allende: It Is Fun

NASA Technical Reports Server (NTRS)

Liu, M.-C.; Keller, L. P.; McKeegan, K. D.

2016-01-01

Introduction: Hibonite-rich refractory inclusions are among the first solids that formed in the solar nebula, and thus provide constraints on the earliest environment in the Solar System. An unusual hibonite-perovskite inclusion from Allende, SHAL, consists of a large (approximately 500 by 200 microns) single hibonite crystal and coexisting blocky perovskite (approximately 200 microns in size). The hibonite is characterized by chemical and oxygen isotopic compositions similar to those in the FUN (Fractionated and Unknown Nuclear anomalies) inclusion HAL. However, the rare earth element (REE) patterns measured at different spots of SHAL hibonite are highly variable, ranging from Group II-like (light REEs enriched relative to heavy REEs) to Group III-like (relatively flat with slight Eu depletions), but overall contrast largely with that of HAL, especially in the Ce and Yb abundances. This implies that SHAL hibonite formed and underwent distillation processes under more reducing conditions. Interestingly, the accompanying perovskite has uniform, unfractionated oxygen isotopic compositions (averaging delta (sup 17) O equals delta (sup 18) O equals -7 per mille) and REE abundances that are completely different from those of SHAL hibonite. This has been interpreted that perovskite and hibonite may not be co-genetic. Here we performed Al-Mg and Ti isotopic measurements of SHAL hibonite and perovskite to determine if the FUN characteristics are observed in these two isotope systems, and to further constrain the origin and evolution of SHAL. Results: Isotopic measurements of Al-Mg and Ti in SHAL were performed on the UCLA CAMECA ims-1290 ion microprobe by following the analytical protocols described in [1]. The Al-Mg and Ti data obtained in both terrestrial standards and SHAL hibonite and perovskite are shown below. Both SHAL hibonite and perovskite, despite very high (sup 27) Al to (sup 24) Mg ratios, are devoid of (sup 26) Mg excesses that can be attributed to the decay of (sup 26) Al. Delta (sup 25) Mg (mass-dependent fractionation) in hibonite is approximately -5 per mille per atomic mass unit relative to Madagascar hibonite, but is not well constrained for perovskite due to very large uncertainties owing to extremely low Mg contents. Similar to Mg isotopes, SHAL hibonite and perovskite show essentially the same Ti isotopic compositions, with anomalies in (sup 50) Ti of approximately 14 per mille, but the former shows greater Ti isotope fractionation than the latter (2.5 per mille per atomic mass unit versus 0 per mille). Discussion and Conclusions: The Al-Mg and Ti isotopic compositions of SHAL hibonite are consistent with those of HAL, suggesting that SHAL hibonite is a FUN inclusion and likely formed prior to homogenization of (sup 26) Al and Ti isotope variations in the solar nebula. However, the formation mechanisms for SHAL and HAL differ, given the differences in the REE patterns and degrees of oxygen mass-dependent fractionation. The Group-II to Group-III like REE patterns, the Yb depletions, and negative delta (sup 25) Mg observed in SHAL hibonite are all consistent with condensation of the hibonite precursor in a reducing environment.. The lack of large Ce depletions in SHAL hibonite implies that distillation processes that fractionated hibonite's oxygen isotopes must have taken place under a reducing condition, but the extent to which SHAL hibonite was distilled appears to be less than HAL because of the smaller degree of oxygen mass-dependent fractionation. The perovskite shares essentially the same Ti and Mg isotopic compositions as hibonite and probably formed in the same reservoir.. The ultrarefractory REE pattern seen in perovskite likely resulted from gas-solid fractionation which depleted HREEs in this reservoir. This process also explains why SHAL hibonite is generally depleted in HREEs relative to LREEs.

The oligocene Lund Tuff, Great Basin, USA: A very large volume monotonous intermediate

USGS Publications Warehouse

Maughan, L.L.; Christiansen, E.H.; Best, M.G.; Gromme, C.S.; Deino, A.L.; Tingey, D.G.

2002-01-01

Unusual monotonous intermediate ignimbrites consist of phenocryst-rich dacite that occurs as very large volume (> 1000 km3) deposits that lack systematic compositional zonation, comagmatic rhyolite precursors, and underlying plinian beds. They are distinct from countless, usually smaller volume, zoned rhyolite-dacite-andesite deposits that are conventionally believed to have erupted from magma chambers in which thermal and compositional gradients were established because of sidewall crystallization and associated convective fractionation. Despite their great volume, or because of it, monotonous intermediates have received little attention. Documentation of the stratigraphy, composition, and geologic setting of the Lund Tuff - one of four monotonous intermediate tuffs in the middle-Tertiary Great Basin ignimbrite province - provides insight into its unusual origin and, by implication, the origin of other similar monotonous intermediates. The Lund Tuff is a single cooling unit with normal magnetic polarity whose volume likely exceeded 3000 km3. It was emplaced 29.02 ?? 0.04 Ma in and around the coeval White Rock caldera which has an unextended north-south diameter of about 50 km. The tuff is monotonous in that its phenocryst assemblage is virtually uniform throughout the deposit: plagioclase > quartz ??? hornblende > biotite > Fe-Ti oxides ??? sanidine > titanite, zircon, and apatite. However, ratios of phenocrysts vary by as much as an order of magnitude in a manner consistent with progressive crystallization in the pre-eruption chamber. A significant range in whole-rock chemical composition (e.g., 63-71 wt% SiO2) is poorly correlated with phenocryst abundance. These compositional attributes cannot have been caused wholly by winnowing of glass from phenocrysts during eruption, as has been suggested for the monotonous intermediate Fish Canyon Tuff. Pumice fragments are also crystal-rich, and chemically and mineralogically indistinguishable from bulk tuff. We postulate that convective mixing in a sill-like magma chamber precluded development of a zoned chamber with a rhyolitic top or of a zoned pyroclastic deposit. Chemical variations in the Lund Tuff are consistent with equilibrium crystallization of a parental dacitic magma followed by eruptive mixing of compositionally diverse crystals and high-silica rhyolite vitroclasts during evacuation and emplacement. This model contrasts with the more systematic withdrawal from a bottle-shaped chamber in which sidewall crystallization creates a marked vertical compositional gradient and a substantial volume of capping-evolved rhyolite magma. Eruption at exceptionally high discharge rates precluded development of an underlying plinian deposit. The generation of the monotonous intermediate Lund magma and others like it in the middle Tertiary of the western USA reflects an unusually high flux of mantle-derived mafic magma into unusually thick and warm crust above a subducting slab of oceanic lithosphere. ?? 2002 Elsevier Science B.V. All rights reserved.

Identification of the n-1 fatty acid as an antibacterial constituent from the edible freshwater cyanobacterium Nostoc verrucosum.

PubMed

Oku, Naoya; Yonejima, Kohsuke; Sugawa, Takao; Igarashi, Yasuhiro

2014-01-01

The cyanobacterium Nostoc verrucosum occurs in cool, clear streams and its gelatinous colonies, called "ashitsuki," have been eaten in ancient Japan. Its ethanolic extract was found to inhibit the growth of Gram-positive bacteria and activity-guided fractionation yielded an unusual n-1 fatty acid, (9Z,12Z)-9,12,15-hexadecatrienoic acid (1), as one of the active principles. It inhibited the growth of Staphylococcus aureus at MIC 64 μg/mL.

Juvenile Granulosa Cell Tumour: Anaplastic Variant with Omental Deposits

PubMed Central

Rao, Anuradha C.K.; Monappa, Vidya

2016-01-01

Juvenile Granulosa Cell Tumour (JGCT) of ovary represents a small fraction of all primary ovarian malignancies. It is a subtype of granulosa cell tumour that is almost always found during the first three decades of life. Histologically, it differs from the typical adult type of granulosa cell tumour. It accounts for 5-15% of all granulosa cell tumours, majority being unilateral. Herein, we describe an unusual histopathological variant of JGCT with numerous large cystic spaces, anaplasia and focal syncytiotrophoblast like giant cells. PMID:27042471

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

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.

Bulk and Thin film Properties of Nanoparticle-based Ionic Materials

NASA Astrophysics Data System (ADS)

Fang, Jason

2008-03-01

Nanoparticle-based ionic materials (NIMS) offer exciting opportunities for research at the forefront of science and engineering. NIMS are hybrid particles comprised of a charged oligomeric corona attached to hard, inorganic nanoparticle cores. Because of their hybrid nature, physical properties --rheological, optical, electrical, thermal - of NIMS can be tailored over an unusually wide range by varying geometric and chemical characteristics of the core and canopy and thermodynamic variables such as temperature and volume fraction. On one end of the spectrum are materials with a high core content, which display properties similar to crystalline solids, stiff waxes, and gels. At the opposite extreme are systems that spontaneously form particle-based fluids characterized by transport properties remarkably similar to simple liquids. In this poster I will present our efforts to synthesize NIMS and discuss their bulk and surface properties. In particular I will discuss our work on preparing smart surfaces using NIMS.

On the chemical composition of L-chondrites

NASA Technical Reports Server (NTRS)

Neal, C. W.; Dodd, R. T.; Jarosewich, E.; Lipschutz, M. E.

1980-01-01

Radiochemical neutron activation analysis of Ag, As, Au, Bi, Co, Cs, Ga, In, Rb, Sb, Te, Tl, and Zn and major element data in 14 L4-6 and 3 LL5 chondrites indicates that the L group is unusually variable and may represent at least 2 subgroups differing in formation history. Chemical trends in the S/Fe rich subgroup support textural evidence indicating late loss of a shock formed Fe-Ni-S melt; the S/Fe poor subgroup seemingly reflects nebular fractionation only. Highly mobile In and Zn apparently reflect shock induced loss from L chondrites. However, contrasting chemical trends in several L chondrite sample sets indicate that these meteorites constitute a more irregular sampling of, or more heterogeneous parent material than do carbonaceous or enstatite chondrites. Data for 15 chondrites suggest higher formation temperatures and/or degrees of shock than for LL5 chondrites.

CYTOMEGALOVIRUS VECTORS VIOLATE CD8+ T CELL EPITOPE RECOGNITION PARADIGMS

PubMed Central

Hansen, Scott G.; Sacha, Jonah B.; Hughes, Colette M.; Ford, Julia C.; Burwitz, Benjamin J.; Scholz, Isabel; Gilbride, Roxanne M.; Lewis, Matthew S.; Gilliam, Awbrey N.; Ventura, Abigail B.; Malouli, Daniel; Xu, Guangwu; Richards, Rebecca; Whizin, Nathan; Reed, Jason S.; Hammond, Katherine B.; Fischer, Miranda; Turner, John M.; Legasse, Alfred W.; Axthelm, Michael K.; Edlefsen, Paul T.; Nelson, Jay A.; Lifson, Jeffrey D.; Früh, Klaus; Picker, Louis J.

2013-01-01

CD8+ T cell responses focus on a small fraction of pathogen- or vaccine-encoded peptides, and for some pathogens, these restricted recognition hierarchies limit the effectiveness of anti-pathogen immunity. We found that simian immunodeficiency virus (SIV) protein-expressing Rhesus Cytomegalovirus (RhCMV) vectors elicit SIV-specific CD8+ T cells that recognize unusual, diverse and highly promiscuous epitopes, including dominant responses to epitopes restricted by class II major histocompatibility complex (MHC) molecules. Induction of canonical SIV epitope-specific CD8+ T cell responses is suppressed by the RhCMV-encoded Rh189 (US11) gene, and the promiscuous MHC class I- and class II-restricted CD8+ T cell responses only occur in the absence of the Rh157.4-.6 (UL128-131) genes. Thus, CMV vectors can be genetically programmed to achieve distinct patterns of CD8+ T cell epitope recognition. PMID:23704576

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

Modic, K. A.; Ramshaw, Brad J.; Betts, J. B.

Here, the complex antiferromagnetic orders observed in the honeycomb iridates are a double-edged sword in the search for a quantum spin-liquid: both attesting that the magnetic interactions provide many of the necessary ingredients, while simultaneously impeding access. Focus has naturally been drawn to the unusual magnetic orders that hint at the underlying spin correlations. However, the study of any particular broken symmetry state generally provides little clue about the possibility of other nearby ground states. Here we use magnetic fields approaching 100 Tesla to reveal the extent of the spin correlations in γ-lithium iridate. We find that a small componentmore » of field along the magnetic easy-axis melts long-range order, revealing a bistable, strongly correlated spin state. Far from the usual destruction of antiferromagnetism via spin polarization, the high-field state possesses only a small fraction of the total iridium moment, without evidence for long-range order up to the highest attainable magnetic fields.« less

Management of Heart Failure in Advancing CKD: Core Curriculum 2018.

PubMed

House, Andrew A

2018-02-23

Heart failure and chronic kidney disease have increasing incidence and prevalence owing in part to the aging population and increasing rates of hypertension, diabetes, and other cardiovascular and kidney disease risk factors. The presence of one condition also has a strong influence on the other, leading to greater risks for hospitalization, morbidity, and death, as well as very high health care costs. Despite the frequent coexistence of heart failure and chronic kidney disease, many of the pivotal randomized trials that guide the management of heart failure have excluded patients with more advanced stages of chronic kidney disease. In this Core Curriculum article, management of a challenging, yet not unusual, case of heart failure with reduced ejection fraction in a patient with stage 4 chronic kidney disease provides an opportunity to review the relevant literature and highlight gaps in our knowledge. Copyright © 2018 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Charge state distribution and emission characteristics in a table top reflex discharge - Effect of ion confinement and electrons accelerated across the sheath

DOE PAGES

Kumar, Deepak; Englesbe, Alexander; Parman, Matthew; ...

2015-11-05

Tabletop reflex discharges in a Penning geometry have many applications including ion sources and eXtreme Ultra-Violet (XUV) sources. The presence of primary electrons accelerated across the cathode sheaths is responsible for the distribution of ion charge states and of the unusually high XUV brightness of these plasmas. Absolutely calibrated space resolved XUV spectra from a table top reflex discharge operating with Al cathodes and Ne gas are presented. The spectra are analyzed with a new and complete model for ion charge distribution in similar reflex discharges. The plasma in the discharge was found to have a density of ~10 18mmore » –3 with a significant fraction >0.01 of fast primary electrons. As a result, the implications of the new model on the ion states achievable in a tabletop reflex plasma discharge are also discussed.« less

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.

Between Scylla and Charybdis: Hydrophobic Graphene-Guided Water Diffusion on Hydrophilic Substrates

PubMed Central

Kim, Jin-Soo; Choi, Jin Sik; Lee, Mi Jung; Park, Bae Ho; Bukhvalov, Danil; Son, Young-Woo; Yoon, Duhee; Cheong, Hyeonsik; Yun, Jun-Nyeong; Jung, Yousung; Park, Jeong Young; Salmeron, Miquel

2013-01-01

The structure of water confined in nanometer-sized cavities is important because, at this scale, a large fraction of hydrogen bonds can be perturbed by interaction with the confining walls. Unusual fluidity properties can thus be expected in the narrow pores, leading to new phenomena like the enhanced fluidity reported in carbon nanotubes. Crystalline mica and amorphous silicon dioxide are hydrophilic substrates that strongly adsorb water. Graphene, on the other hand, interacts weakly with water. This presents the question as to what determines the structure and diffusivity of water when intercalated between hydrophilic substrates and hydrophobic graphene. Using atomic force microscopy, we have found that while the hydrophilic substrates determine the structure of water near its surface, graphene guides its diffusion, favouring growth of intercalated water domains along the C-C bond zigzag direction. Molecular dynamics and density functional calculations are provided to help understand the highly anisotropic water stripe patterns observed. PMID:23896759

ALH85085: a unique volatile-poor carbonaceous chondrite with possible implications for nebular fractionation processes

USGS Publications Warehouse

Grossman, J.N.; Rubin, A.E.; MacPherson, G.J.

1988-01-01

Allan Hills 85085 is a unique chondrite with affinities to the Al Rais-Renazzo clan of carbonaceous chondrites. Its constituents are less than 50 ??m in mean size. Chondrules and microchondrules of all textures are present; nonporphyritic chondrules are unusually abundant. The mean compositions of porphyritic, nonporphyritic and barred olivine chondrules resemble those in ordinary chondrites except that they are depleted in volatile elements. Ca-, Al-rich inclusions are abundant and largely free of nebular alteration; they comprise types similar to those in CM and CO chondrites, as well as unique types. Calcium dialuminate occurs in several inclusions. Metal, silicate and sulfide compositions are close to those in CM-CO chondrites and Al Rais and Renazzo. C1-chondrite clasts and metal-rich "reduced" clasts are present, but opaque matrix is absent. Siderophile abundances in ALH85085 are extremely high (e.g., Fe Si = 1.7 ?? solar), and volatiles are depleted (e.g., Na Si = 0.25 ?? solar, S Si = 0.03 ?? solar). Nonvolatile lithophile abundances are similar to those in Al Rais, Renazzo, and CM and CO chondrites. ALH85085 agglomerated when temperatures in the nebula were near 1000 K, in the same region where Renazzo, Al Rais and the CI chondrites formed. Agglomeration of high-temperature material may thus be a mechanism by which the fractionation of refractory lithophiles occurred in the nebula. Chondrule formation must have occurred at high temperatures when clumps of precursors were small. After agglomeration, ALH85085 was annealed and lightly shocked. C1 and other clasts were subsequently incorporated during late-stage brecciation. ?? 1988.

The negative and positive electrorheological behavior and vibration damping characteristics of colemanite and polyindene/colemanite conducting composite

NASA Astrophysics Data System (ADS)

Cetin, B.; Unal, H. I.; Erol, O.

2012-12-01

In this study, the electrorheological (ER) properties of colemanite and polyindene (94.8% PIn)/colemanite (5.2%) conducting composite were investigated by dispersion in silicone oil (SO). The zeta (ζ)-potentials and antisedimentation ratios of the materials were determined. Some parameters which affect the ER properties of all the dispersions such as the volume fraction, electric field strength (E), shear rate, frequency and temperature were investigated. The rather unusual behavior known as the negative ER effect was observed for colemanite/SO above E = 1.5 kV mm-1 and for PIn/colemanite/SO under all values of the electric field strength even at high volume fraction. This negative ER response was converted to a positive one by the addition of non-ionic surfactant. Furthermore, glycerol was used as a polar promoter and observed to enhance the ER activity of the colemanite/SO system. Creep-recovery tests were applied to all the dispersions studied to investigate their behavior under sustained shear stress. Finally, 28% and 30% vibration damping capacities were achieved using an automobile shock absorber for the glycerol/colemanite/SO and non-ionic surfactant/PIn/colemanite/SO systems under the E = 0.17 kV mm-1 condition, respectively.

The chemistry of rare earth elements in the solar nebula

NASA Technical Reports Server (NTRS)

Larimer, J. W.; Bartholomay, H. A.; Fegley, B.

1984-01-01

The high concentration of rare earth elements (REE) in primitive CaS suggests that the REE along with the other normally lithophile elements form stable sulfides under the unusual conditions which existed during the formation of enstatite chrondites. In order to acquire a more quantitative framework in which to interpret these data, the behavior of the REE in systems with solar, or slightly fractionated solar, composition is being studied. These new data introduce modest changes in the behavior of some of the REE when compared to previous studies. For example, the largest differences are in the stabilities of the gaseous monoxides of Ce, Eu, Tb, Ho, and Tm, all of which now appear to be less stable than previously thought, and YbO(g) which is somewhat more stable. Much more significant are the changes in REE distribution in the gas phase in fractionated systems, especially those made more reducing by changing the C/O ratio from the solar value of 0.6 to about 1.0. In almost all cases, the exceptions being Eu, Tm and Yb whose elemental gaseous species dominate, the monosulfides become more abundant. Moreover, the solid oxides of Eu, Tm and Yb become less stable under more reducing conditions which, in effect, should reduce the condensation temperature of all REE in more reduced systems.

The Other Major 2010 Oil Spill: Oil weathering after the Kalamazoo River Dilbit Spill

NASA Astrophysics Data System (ADS)

Swarthout, B.; Reddy, C. M.; Nelson, R. K.; Hamilton, S. K.; Aeppli, C.; Valentine, D. L.; Fundaun, S. E.; Oliveira, A. H.

2016-02-01

Diluted bitumen (dilbit) from the oil sands (tar sands) of western Canada is increasingly being transported to US markets. North America's largest inland oil spill and the first major oil sands spill in a freshwater environment occurred in 2010, when at least 843,000 gallons leaked from a pipeline into the Kalamazoo River of southwest Michigan. Cleanup of this oil was unusually difficult and protracted, lasting through 2014 and costing over a billion dollars, largely because a substantial fraction of the oil became submersed and deposited in slack water areas over 60 km of river channel, reservoirs, and floodplain backwaters. To investigate the fate of the spilled dilbit from the 2010 Kalamazoo River release, black rings, presumably oil residues, on the bark of dead trees were collected in 2015. These residues were deposited on the trees during high flood levels that have not been observed since the spill and represent an opportunity to constrain weathering processes excluding dissolution. This material contained a major non-GC amenable fraction of 90-95%, presumably oxygenated hydrocarbons. The GC amenable portion was consistent with laboratory weathered dilbit. We used a variety of analytical tools to characterize the dilbit residues, as well as to identify dilbit weathering processes that occurred since the spill.

Analysis of oversulfation in biglycan chondroitin/dermatan sulfate oligosaccharides by chip-based nanoelectrospray ionization multistage mass spectrometry.

PubMed

Flangea, Corina; Sisu, Eugen; Seidler, Daniela G; Zamfir, Alina D

2012-01-15

Biglycan (BGN) is a small proteoglycan that consists of a protein core containing leucine-rich repeat regions and two glycosaminoglycan (GAG) chains of either chondroitin sulfate (CS) or dermatan sulfate (DS) type. The development of novel, highly efficient analytical methods for structural identification of BGN-derived CS/DS motifs, possibly implicated in biological events, is currently the focus of research. In this work, an improved analytical method based on fully automated chip-nanoelectrospray ionization (nanoESI) in conjunction with high-capacity ion trap (HCT) multistage mass spectrometry (MS) by collision-induced dissociation (CID) was for the first time applied to BGN CS/DS oligosaccharide analysis. The CS/DS chains were released from transfected 293 BGN by β-elimination. The chain was digested with AC I lyase, and the resulting mixture was purified and subsequently separated by size exclusion chromatography (SEC). Di- and tetrasaccharide fractions were pooled and characterized in detail using the developed chip-nanoESI protocol. The chip-nanoESI MS profile in the negative ion mode revealed the presence of under-, regularly, and oversulfated species in both di- and tetrasaccharide fractions. CID MS(2)-MS(3) yielded sequence patterns consistent with unusual oversulfated 4,5-Δ-GlcA(2S)-GalNAc(4S) and 4,5-Δ-GlcA(2S)-GalNAc(6S)-IdoA(2S)-GalNAc(6S) motifs. Copyright © 2011 Elsevier Inc. All rights reserved.

THE X-RAY SPECTRUM OF THE COOLING-FLOW QUASAR H1821+643: A MASSIVE BLACK HOLE FEEDING OFF THE INTRACLUSTER MEDIUM

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

Reynolds, Christopher S.; Lohfink, Anne M.; Babul, Arif

2014-09-10

We present a deep Suzaku observation of H1821+643, an extremely rare example of a powerful quasar hosted by the central massive galaxy of a rich cooling-core cluster of galaxies. Informed by previous Chandra studies of the cluster, we achieve a spectral separation of emission from the active galactic nucleus (AGN) and the intracluster medium (ICM). With a high degree of confidence, we identify the signatures of X-ray reflection/reprocessing by cold and slowly moving material in the AGN's immediate environment. The iron abundance of this matter is found to be significantly sub-solar (Z ≈ 0.4 Z {sub ☉}), an unusual findingmore » for powerful AGN but in line with the idea that this quasar is feeding from the ICM via a Compton-induced cooling flow. We also find a subtle soft excess that can be described phenomenologically (with an additional blackbody component) or as ionized X-ray reflection from the inner regions of a high inclination (i ≈ 57°) accretion disk around a spinning (a > 0.4) black hole. We describe how the ionization state of the accretion disk can be used to constrain the Eddington fraction of the source. Applying these arguments to our spectrum implies an Eddington fraction of 0.25-0.5, with an associated black hole mass of 3--6×10{sup 9} M{sub ⊙}.« less

Development of a High Resolution-High Sensitivity Ion Microprobe Facility for Cosmochemical Applications

NASA Technical Reports Server (NTRS)

McKeegan, Kevin D.

1998-01-01

NASA NAGW-4112 has supported development of the CAMECA ims 1270 ion microprobe at UCLA for applications in cosmochemistry. The instrument has been brought to an operational status and techniques developed for accurate, precise microbeam analysis of oxygen isotope ratios in polished thin-sections. We made the first oxygen isotopic (delta(18)O and delta(17)O) measurements of rare mafic silicates in the most chemically primitive meteorites, the a chondrites (Leshin et al., 1997). The results have implications for both high temperature processing in the nebula and low-T aqueous alteration on the CI asteroid. We have performed measurements of oxygen isotopic compositions of magnetite and co-existing olivine from carbonaceous (Choi et al., 1997) and unequilibrated ordinary chondrites (Choi et al., in press). This work has identified a significant new oxygen isotope reservoir in the early solar system: water characterized by a very high Delta(17)) value of approx. 5 % per thousand. We have determined the spatial distributions of oxygen isotopic anomalies in all major mineral phases of a type B CAI from Allende. We have also studied an unusual fractionated CAI from Leoville and made the first oxygen isotopic measurements in rare CAIs from ordinary chondrites.

Watson: A new link in the IIE iron chain

NASA Technical Reports Server (NTRS)

Olsen, Edward; Davis, Andrew; Clarke, Roy S., Jr.; Schultz, Ludolf; Weber, Hartwig W.; Clayton, Robert; Mayeda, Toshiko; Jarosewich, Eugene; Sylvester, Paul; Grossman, Lawrence

1994-01-01

Watson, which was found in 1972 in South Australia, contains the largest single silicate rock mass seen in any known iron meteorite. A comprehensive study has been completed on this unusual meteorite: petrography, metallography, analyses of the silicate inclusion (whole rock chemical analysis, INAA, RNAA, noble gases, and oxygen isotope analysis) and mineral compositions (by electron microprobe and ion microprobe). The whole rock has a composition of an H-chondrite minus the normal H-group metal and troilite content. The oxygen isotope composition is that of the silicates in the IIE iron meteorites and lies along an oxygen isotope fractionation line with the H-group chondrites. Trace elements in the metal confirm Watson is a new IIE iron. Whole rock Watson silicate shows an enrichment in K and P (each approximately 2X H-chondrites). The silicate inclusion has a highly equilibrated igneous (peridotite-like) texture with olivine largely poikilitic within low-Ca pyroxene: olivine (Fa20), opx (Fs17Wo3), capx (Fs9Wo14)(with very fine exsolution lamellae), antiperthite feldspar (An1-3Or5) with less than 1 micron exsolution lamellae (An1-3Or greater than 40), shocked feldspar with altered stoichiometry, minor whitlockite (also a poorly characterized interstitial phosphate-rich phase) and chromite, and only traces of metal and troilite. The individual silicate minerals have normal chondritic REE patterns, but whitlockite has a remarkable REE pattern. It is very enriched in light REE (La is 720X C1, and Lu is 90X C1, as opposed to usual chonditic values of approximately 300X and 100-150X, respectively) with a negative Eu anomaly. The enrichment of whole rock K is expressed both in an unusually high mean modal Or content of the feldspar, Or13, and in the presence of antiperthite.

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.

Primary cumulus platinum minerals in the Monts de Cristal Complex, Gabon: magmatic microenvironments inferred from high-definition X-ray fluorescence microscopy

NASA Astrophysics Data System (ADS)

Barnes, Stephen J.; Fisher, Louise A.; Godel, Bélinda; Pearce, Mark A.; Maier, Wolfgang D.; Paterson, David; Howard, Daryl L.; Ryan, Christopher G.; Laird, Jamie S.

2016-03-01

An unusual occurrence of Pt-enriched pyroxenites in the Monts de Cristal igneous complex is characterized by unusually high ratios of Pt to other platinum-group elements (PGEs) and very low Cu and sulfide contents. Synchrotron X-ray fluorescence microscopy was used to identify over a hundred discrete grains of platinum minerals and relate their occurrence to textural associations in the host heteradcumulate orthopyroxenites. Element associations, backed up by FIB-SEM and PIXE probe observations, indicate that most of the Pt is associated with either As- or trace Cu-Ni-rich sulfides, or both. Some of the Pt-As grains can be identified as sperrylite, and most are likely to be Pt-Fe alloy. The relative abundances and volumes of Pt minerals to sulfide minerals are very large compared with typical magmatic sulfides. Almost all of the grains observed lie at or within a few tens of μm of cumulus orthopyroxene grain boundaries, and there is no significant difference between the populations of grains located inside or outside plagioclase oikocrysts. These oikocrysts are inferred to have crystallized either at the cumulus stage or very shortly thereafter, on the basis of their relationship to Ti enrichment in the margins of pyroxene grains not enclosed in oikocrysts. This relationship precludes a significant role of trapped intercumulus liquid in Pt deposition or mobilization and also allows a confident inference that Pt-rich and Pt-As-enriched phases precipitated directly from the magma at the cumulus stage. These observations lead to the conclusion that fractionation of Pt from other PGEs in this magmatic system is a consequence of a solubility limit for solid Pt metal and/or Pt arsenide.

Anomalous uptake and circulatory characteristics of the plant-based small RNA MIR2911.

PubMed

Yang, Jian; Hotz, Tremearne; Broadnax, LaCassidy; Yarmarkovich, Mark; Elbaz-Younes, Ismail; Hirschi, Kendal D

2016-06-02

Inconsistent detection of plant-based dietary small RNAs in circulation has thwarted the use of dietary RNA therapeutics. Here we demonstrate mice consuming diets rich in vegetables displayed enhanced serum levels of the plant specific small RNA MIR2911. Differential centrifugation, size-exclusion chromatography, and proteinase K treatment of plant extracts suggest this RNA resides within a proteinase K-sensitive complex. Plant derived MIR2911 was more bioavailable than the synthetic RNA. Furthermore, MIR2911 exhibited unusual digestive stability compared with other synthetic plant microRNAs. The characteristics of circulating MIR2911 were also unusual as it was not associated with exosomes and fractionated as a soluble complex that was insensitive to proteinase K treatment, consistent with MIR2911 being stabilized by modifications conferred by the host. These results indicate that intrinsic stability and plant-based modifications orchestrate consumer uptake of this anomalous plant based small RNA and invite revisiting plant-based microRNA therapeutic approaches.

Anomalous uptake and circulatory characteristics of the plant-based small RNA MIR2911

PubMed Central

Yang, Jian; Hotz, Tremearne; Broadnax, LaCassidy; Yarmarkovich, Mark; Elbaz-Younes, Ismail; Hirschi, Kendal D.

2016-01-01

Inconsistent detection of plant-based dietary small RNAs in circulation has thwarted the use of dietary RNA therapeutics. Here we demonstrate mice consuming diets rich in vegetables displayed enhanced serum levels of the plant specific small RNA MIR2911. Differential centrifugation, size-exclusion chromatography, and proteinase K treatment of plant extracts suggest this RNA resides within a proteinase K-sensitive complex. Plant derived MIR2911 was more bioavailable than the synthetic RNA. Furthermore, MIR2911 exhibited unusual digestive stability compared with other synthetic plant microRNAs. The characteristics of circulating MIR2911 were also unusual as it was not associated with exosomes and fractionated as a soluble complex that was insensitive to proteinase K treatment, consistent with MIR2911 being stabilized by modifications conferred by the host. These results indicate that intrinsic stability and plant-based modifications orchestrate consumer uptake of this anomalous plant based small RNA and invite revisiting plant-based microRNA therapeutic approaches. PMID:27251858

Progress Toward Steady State Tokamak Operation Exploiting the high bootstrap current fraction regime

NASA Astrophysics Data System (ADS)

Ren, Q.

2015-11-01

Recent DIII-D experiments have advanced the normalized fusion performance of the high bootstrap current fraction tokamak regime toward reactor-relevant steady state operation. The experiments, conducted by a joint team of researchers from the DIII-D and EAST tokamaks, developed a fully noninductive scenario that could be extended on EAST to a demonstration of long pulse steady-state tokamak operation. Fully noninductive plasmas with extremely high values of the poloidal beta, βp >= 4 , have been sustained at βT >= 2 % for long durations with excellent energy confinement quality (H98y,2 >= 1 . 5) and internal transport barriers (ITBs) generated at large minor radius (>= 0 . 6) in all channels (Te, Ti, ne, VTf). Large bootstrap fraction (fBS ~ 80 %) has been obtained with high βp. ITBs have been shown to be compatible with steady state operation. Because of the unusually large ITB radius, normalized pressure is not limited to low βN values by internal ITB-driven modes. βN up to ~4.3 has been obtained by optimizing the plasma-wall distance. The scenario is robust against several variations, including replacing some on-axis with off-axis neutral beam injection (NBI), adding electron cyclotron (EC) heating, and reducing the NBI torque by a factor of 2. This latter observation is particularly promising for extension of the scenario to EAST, where maximum power is obtained with balanced NBI injection, and to a reactor, expected to have low rotation. However, modeling of this regime has provided new challenges to state-of-the-art modeling capabilities: quasilinear models can dramatically underpredict the electron transport, and the Sauter bootstrap current can be insufficient. The analysis shows first-principle NEO is in good agreement with experiments for the bootstrap current calculation and ETG modes with a larger saturated amplitude or EM modes may provide the missing electron transport. Work supported in part by the US DOE under DE-FC02-04ER54698, DE-AC52-07NA27344, DE-AC02-09CH11466, and the NMCFP of China under 2015GB110000 and 2015GB102000.

Physangulidines A, B, and C: three new antiproliferative withanolides from Physalis angulata L.

PubMed

Jin, Zhuang; Mashuta, Mark S; Stolowich, Neal J; Vaisberg, Abraham J; Stivers, Nicole S; Bates, Paula J; Lewis, Walter H; Hammond, Gerald B

2012-03-02

Bioassay-directed fractionation of the whole plant of Physalis angulata L. afforded three new antiproliferative withanolides with an unusual carbon framework: physangulidines A (1), B (2), and C (3). Structures of the three isomeric withanolides were determined by a combination of HRMS, NMR spectroscopic, and X-ray crystallographic methods. Each has shown significant antiproliferative activity against DU145 prostate cancer cells. Physangulidine A (1) was further tested against a wide range of additional cancer cell lines and found to exhibit significant antiproliferative activity. © 2012 American Chemical Society

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

Nature of the lithospheric mantle beneath the Arabian Shield and genesis of Al-spinel micropods: Evidence from the mantle xenoliths of Harrat Kishb, Western Saudi Arabia

NASA Astrophysics Data System (ADS)

Ahmed, Ahmed H.; Moghazi, Abdel Kader M.; Moufti, Mohamed R.; Dawood, Yehia H.; Ali, Kamal A.

2016-01-01

The Harrat Kishb area of western Saudi Arabia is part of the Cenozoic volcanic fields in the western margin of the Arabian Shield. Numerous fresh ultramafic xenoliths are entrained in the basanite lava of Harrat Kishb, providing an opportunity to study the nature and petrogenetic processes involved in the evolution of the lithospheric mantle beneath the Arabian Shield. Based on the petrological characteristics and mineralogical compositions, the majority of the mantle xenoliths ( 92%) are peridotites (lherzolites and pyroxene-bearing harzburgites); the remaining xenoliths ( 8%) are unusual spinel-rich wehrlites containing black Al-spinel micropods. The two types of mantle xenoliths display magmatic protogranular texture. The peridotite xenoliths have high bulk-rock Mg#, high forsterite (Fo90-Fo92) and NiO (0.24-0.46 wt.%) contents of olivine, high clinopyroxene Mg# (0.91-0.93), variable spinel Cr# (0.10-0.49, atomic ratio), and approximately flat chondrite-normalized REE patterns. These features indicate that the peridotite xenoliths represent residues after variable degrees of melt extraction from fertile mantle. The estimated P (9-16 kbar) and T (877-1227 °C) as well as the oxidation state (ΔlogfO2 = - 3.38 to - 0.22) under which these peridotite xenoliths originated are consistent with formation conditions similar to most sub-arc abyssal-type peridotites worldwide. The spinel-rich wehrlite xenoliths have an unusual amount ( 30 vol.%) of Al-spinel as peculiar micropods with very minor Cr2O3 content (< 1 wt.%). Olivines of the spinel-rich wehrlites have low-average Fo (Fo81) and NiO (0.18 wt.%) contents, low-average cpx Mg# (0.79), high average cpx Al2O3 content (8.46 wt.%), and very low-average spinel Cr# (0.01). These features characterize early mantle cumulates from a picritic melt fraction produced by low degrees of partial melting of a garnet-bearing mantle source. The relatively high Na2O and Al2O3 contents of cpx suggest that the spinel-rich wehrlites are formed under high P (11-14 kbar), T (1090-1130 °C), and oxidation state (ΔlogfO2 FMQ = + 0.14 to + 0.37), which occurred slightly below the crust-mantle boundary. The REE patterns of spinel-rich wehrlites are almost similar to those of the associated peridotite xenoliths, which confirm at least a spatial genetic linkage between them. Regarding the formation of Al-spinel micropods in spinel-rich wehrlite cumulates, it is suggested that the melt-rock reaction mechanism is not the only process by which podiform chromitite is formed. Early fractionation of picritic melts produced by partial melting of a mantle source under high P-T conditions could be another mechanism. The cpx composition, not opx, as it was assumed, seems to be the main control of the size and composition of spinel concentrations.

Chemical recognition of kingsnakes by crotalines: effects of size on the ophiophage defensive response.

PubMed

Gutzke, W H; Tucker, C; Mason, R T

1993-01-01

When confronted by an ophiophagous (snake-eating) kingsnake, venomous snakes of the subfamily Crotalinae exhibit a suite of defensive responses including head hiding, thrashing, and an unusual response termed 'body bridging'. Other responses observed, such as biting and 'freezing', are more general in nature and can occur in a variety of contexts. Various crotalines of differing sizes were tested for their responses to kingsnakes (Lampropeltis getulus). Responses of individuals were recorded for up to 18 months. The results indicate that, if habituation can be overcome by periodically allowing a kingsnake to confront but not harm the crotaline, the response is dependent on the size of the crotaline, in that smaller specimens (< 0.9 m) respond readily, while larger snakes (> 1.0 m) tend not to respond. The size of the kingsnake apparently does not have an effect on the crotaline response. These data appear to resolve apparent conflicts in the literature regarding whether certain species respond to ophidian ophiophages. In addition, hexane extracts of kingsnake skin were fractionated using an alumina column. The various fractions obtained were tested to determine which elicited the defensive response. Activity was found only in the most non-polar fraction. Preliminary analysis by gas chromatography/mass spectrometry indicated that this fraction contained straight and branched, saturated and polyunsaturated long-chain hydrocarbons.

Polybaric evolution of phonolite, trachyte, and rhyolite volcanoes in Eastern Marie Byrd Land, Antarctica: Controls on peralkalinity and silica saturation

USGS Publications Warehouse

LeMasurier, W.E.; Futa, K.; Hole, M.; Kawachi, Y.

2003-01-01

In the Marie Byrd Land volcanic province, peralkaline and metaluminous trachytes, phonolites, and rhyolites occur in 18 large shield volcanoes that are closely associated in time and space. They are arrayed radially across an 800 km wide structural dome, with the oldest at the crest and the youngest around the flanks. Several lines of evidence suggest that these rocks evolved via open-system, polybaric fractionation. We have used mass balance modeling of major elements together with trace-element data and mineral chemistry to help explain the evolution of this diverse suite of felsic rocks, which appear to have been generated coevally in isolated magma chambers, and erupted close to each other in patterns related to tectonic uplift and extension within the West Antarctic rift system. Isotopic and trace-element data indicate that this occurred with only minimal crustal contamination. We focus on volcanoes of the Executive Committee Range and Mount Murphy, where we find good representation of basalts and felsic rocks within a small area. Our results suggest that the felsic rocks were derived from basaltic magmas that differentiated at multiple levels during their passage to the surface: first to ferrogabbroic compositions near the base of the lithosphere, then to intermediate compositions near the base of the crust, and finally to felsic compositions in mid- to upper crustal reservoirs. The high-pressure history has been largely masked by low-pressure processes. The best indications of a high-pressure history are the mineral phases in cumulate nodules and their correlation with modeling results, with REE anomalies, and with the composition of an unusual gabbroic intrusion. Silica saturation characteristics are believed to have originated in magma chambers near the base of the crust, via fractionation of variable proportions of kaersutite and plagioclase. Development of peralkalinity in felsic rocks took place in upper crustal reservoirs by fractionating a high ratio of plagioclase to clinopyroxene under conditions of low pH2O. With increasing pH2O, the ratio plagioclase/clinopyroxene in the fractionated assemblage decreases and metaluminous liquids resulted. Crustal contamination seems to have had a role in suppressing peralkalinity, and was probably a factor in the origin of high-silica metaluminous rhyolite, but metaluminous rocks are uncommon. The volume and diversity of felsic rocks were probably enhanced by the structure of the lithosphere, the persistence of plume activity, and the immobility of the Antarctic plate. Mechanical boundaries at the base of the lithosphere and crust, and within the crust, appear to have acted as filters, trapping magmas at multiple levels, and prolonging the fractionation process. Final volumes would have been further enhanced by repeated refluxing of the same magma chambers, controlled by plume activity and plate immobility.

On the structural stability of guanosine-based supramolecular hydrogels.

PubMed

Carducci, Federica; Yoneda, Juliana S; Itri, Rosangela; Mariani, Paolo

2018-04-18

Supramolecular hydrogels formed from the self-assembly of low molecular weight derivatives are very attractive systems, because of their potential applications in nano- and bio-technology. In this paper, the stable and transparent hydrogels observed in binary mixtures of guanosine derivatives (G), namely guanosine 5'-monophosphate (GMP) and guanosine (Gua), dissolved in water (at volume fractions larger than 0.95), were investigated by microscopy techniques and Small Angle X-ray Scattering (SAXS). The results confirm the presence of G-quadruplexes, chiral cylindrical rods obtained by the regular stacking of self-assembled planar cyclic guanosine quartets. However, the addition of Gua determines the formation of very stable hydrogels able to trap large amounts of water (up to a volume fraction of 0.99) and characterised by an unusual anisotropic order. A modified lateral helix-to-helix interaction pattern, tuned by Gua, is suggested to be responsible for the supramolecular gelation and the stability of the hydrogels during swelling.

Topological model of composite fermions in the cyclotron band generator picture: New insights

NASA Astrophysics Data System (ADS)

Staśkiewicz, Beata

2018-03-01

A combinatorial group theory in the braid groups is correlated with the unusual "anyon" statistic of particles in 2D Hall system in the fractional quantum regime well. On this background has been derived cyclotron band generator as a modification and generalization band generator, first established to solve the word and conjugacy problems in the braid group terms. Topological commensurability condition has been embraced by canonical factors - like, based on the concept of parallel descending cycles. Owing to this we can mathematically capture the general hierarchy of correlated states in the lowest Landau level, describing the fractional quantum Hall effect hierarchy, in terms of cyclotron band generators, especially for those being beyond conventional composite fermions model. It has been also shown that cyclotron braid subgroups, developed for interpretation of Laughlin correlations, are a special case of the right-angled Artin groups.

Resolving the Many Mysteries of Martian Soil: Lessons Learned from Apollo

NASA Astrophysics Data System (ADS)

Pieters, C. M.

1999-09-01

If it were not for the return of lunar soil, we would still not understand why the spectrum of lunar soil is so unusual. We observe the intricacies of particles in the laboratory, but have never been able to duplicate the effects of weathering processes accumulated over time. We are in a directly parallel situation with our current understanding of Martian soil from spectroscopic techniques. We know it contains a ferric component and we know something of its elemental composition; we know it is very fine grained; we know it is the cumulative weathering product of Martian lithologies, some of which are known from meteorites. A summary of several relevant lessons from studying lunar soils include: 1) Physical and chemical processes fractionate the soils with respect to local rocks. 2) Meteoritic contamination (largely from the constant rain of micrometeorites) cumulates in the soils. Lunar estimates are about 2-3 percent. 3) The fine fraction dominate observed optical properties, regardless of the presence of larger particles. Individual particles may accumulate coatings and rinds. 4) The spectral characteristics of the weathering products of iron dominate soil spectra. On the Moon it is highly reduced iron (typically 10's of nm in scale); on Mars it is highly oxidized (nano-phase?) iron. Modeling this 'gunk' or 'crud' is illusive. 5) Although weathering products dominate most spectra, signatures of the mineralogy of regional terrain can nevertheless be detected as subtle superimposed features. 6) Small-scale outcrops where soil has not been able to form or accumulate are critical markers of local lithology diversity. In planning exploration strategies using remote detectors, this latter lesson is particularly important and underlines the need for high resolution.

A detailed investigation of the strain hardening response of aluminum alloyed Hadfield steel

NASA Astrophysics Data System (ADS)

Canadinc, Demircan

The unusual strain hardening response exhibited by Hadfield steel single and polycrystals under tensile loading was investigated. Hadfield steel, which deforms plastically through the competing mechanisms slip and twinning, was alloyed with aluminum in order to suppress twinning and study the role of slip only. To avoid complications due to a grained structure, only single crystals of the aluminum alloyed Hadfield steel were considered at the initial stage of the current study. As a result of alloying with aluminum, twinning was suppressed; however a significant increase in the strain hardening response was also present. A detailed microstructural analysis showed the presence of high-density dislocation walls that evolve in volume fraction due to plastic deformation and interaction with slip systems. The very high strain hardening rates exhibited by the aluminum alloyed Hadfield steel single crystals was attributed to the blockage of glide dislocations by the high-density dislocation walls. A crystal plasticity model was proposed, that accounts for the volume fraction evolution and rotation of the dense dislocation walls, as well as their interaction with the active slip systems. The novelty of the model lies in the simplicity of the constitutive equations that define the strain hardening, and the fact that it is based on experimental data regarding the microstructure. The success of the model was tested by its application to different crystallographic orientations, and finally the polycrystals of the aluminum alloyed Hadfield steel. Meanwhile, the capability of the model to predict texture was also observed through the rotation of the loading axis in single crystals. The ability of the model to capture the polycrystalline deformation response provides a venue for its utilization in other alloys that exhibit dislocation sheet structures.

Unveiling Quasar Fueling through a Public Snapshot Survey of Quasar Host Environments

NASA Astrophysics Data System (ADS)

Johnson, Sean

2017-08-01

Feedback from quasars is thought to play a vital role in galaxy evolution, but the relationship between quasars and the halo gas that fuels star-formation on long timescales is not well constrained. Recent observations of the content of quasar host halos have found unusually high covering fractions of cool gas observed in absorption in background quasar spectra. The cool halo gas is strongly correlated with quasar luminosity and exceeds what is observed around non-AGN galaxies by factor of two. Together, these observations provide compelling evidence for a connection between AGN activity and halo gas on 20-200 kpc scales. The high covering fraction and correlation with quasar luminosity may be the result of debris from the galaxy mergers thought to trigger luminous quasars or the halo gas of satellites in gas-rich groups amenable to quasar feeding. If this is the case, then the cool gas observed in absorption will be correlated with signatures of recent galaxy interactions in the quasar host or satellites close to the background sightline. Here, we propose a snapshot imaging survey of z<1 quasars with available constraints on halo gas content to examine a possible correlation between cool halo gas and galaxy interaction signatures. Galaxy morphologies and faint tidal features at z 1 can only be observed with the high resolution imaging capabilities of HST due to the substantial flux in extended wings of AO point-spread functions. The images will be of significant archival value for studying the galaxy environments of quasars and for constraining gas flow models with multi-sightline halo gas studies of galaxies at lower redshift than the foreground & background quasars.

A 120-kDa alkaline peptidase from Trypanosoma cruzi is involved in the generation of a novel Ca(2+)-signaling factor for mammalian cells.

PubMed

Burleigh, B A; Andrews, N W

1995-03-10

Trypomastigotes, the infective stages of the intracellular parasite Trypanosoma cruzi, induce rapid and repetitive cytosolic free Ca2+ transients in fibroblasts. Buffering or depletion of intracellular free Ca2+ inhibits cell entry by trypomastigotes, indicating a role for this signaling event in invasion. We show here that the majority of the Ca(2+)-signaling activity is associated with the soluble fraction of parasites disrupted by sonication. Distinct cell types from different species are responsive to this soluble factor, and intracellular free Ca2+ transients occur rapidly and reach concentrations comparable to responses induced by thrombin and bombesin. The Ca(2+)-signaling activity does not bind concanavalin A and is strongly inhibited by a specific subset of protease inhibitors. The only detectable protease in the fractions with Ca(2+)-signaling activity is an unusual alkaline peptidase of 120 kDa, to which no function had been previously assigned. The activity of the protease and cell invasion by trypomastigotes are blocked by the same specific inhibitors that impair Ca(2+)-signaling, suggesting that the enzyme is required for generating the response leading to infection. We demonstrate that the 120-kDa peptidase is not sufficient for triggering Ca(2+)-signaling, possibly being involved in the processing of precursors present only in infective trypomastigotes. These findings indicate a biological function for a previously identified unusual protozoan protease and provide the first example of a proteolytically generated parasite factor with characteristics of a mammalian hormone.

Volatiles in High-K Lunar Basalts

NASA Technical Reports Server (NTRS)

Barnes, Jessica J.; McCubbin, Francis M.; Messenger, Scott R.; Nguyen, Ann; Boyce, Jeremy

2017-01-01

Chlorine is an unusual isotopic system, being essentially unfractionated ((delta)Cl-37 approximately 0 per mille ) between bulk terrestrial samples and chondritic meteorites and yet showing large variations in lunar (approximately -4 to +81 per mille), martian, and vestan (HED) samples. Among lunar samples, the volatile-bearing mineral apatite (Ca5(PO4)3[F,Cl,OH]) has been studied for volatiles in K-, REE-, and P (KREEP), very high potassium (VHK), low-Ti and high-Ti basalts, as well as samples from the lunar highlands. These studies revealed a positive correlation between in-situ (delta)Cl-37 measurements and bulk incompatible trace elements (ITEs) and ratios. Such trends were interpreted to originate from Cl isotopic fractionation during the degassing of metal chlorides during or shortly after the differentiation of the Moon via a magma ocean. In this study, we investigate the volatile inventories of a group of samples for which new-era volatile data have yet to be reported - the high-K (greater than 2000 ppm bulk K2O), high-Ti, trace element-rich mare basalts. We used isotope imaging on the Cameca NanoSIMS 50L at JSC to obtain the Cl isotopic composition [((Cl-37/(35)Clsample/C-37l/(35)Clstandard)-1)×1000, to get a value in per thousand (per mille)] which ranges from approximately -2.7 +/- 2 per mille to +16.1 +/- 2 per mille (2sigma), as well as volatile abundances (F & Cl) of apatite in samples 10017, 10024 & 10049. Simply following prior models, as lunar rocks with high bulk-rock abundances of ITEs we might expect the high-K, high-Ti basalts to contain apatite characterized by heavily fractionated (delta)Cl-37 values, i.e., Cl obtained from mixing between unfractionated mantle Cl (approximately 0 per mille) and the urKREEP reservoir (possibly fractionated to greater than +25 per mille.). However, the data obtained for the studied samples do not conform to either the early degassing or mixing models. Existing petrogentic models for the origin of the high-K, high-Ti basalts do not include urKREEP assimilation into their LMO cumulate sources. Therefore, Cl in these basalts either originated from source region heterogeneity or through assimilation or metasomatism by volatile and incompatible trace element rich materials. The new data presented here could provide evidence for the existence of region(s) in the lunar interior that are ITE-enriched and contain Cl that does not share isotopic affinities with lunar urKREEP, possibly representing the composition of the purported 'neuKREEP'.

The oxygen evolving enhancer protein 1 (OEE) of photosystem II in green algae exhibits thioredoxin activity.

PubMed

Heide, Heinrich; Kalisz, Henryk M; Follmann, Hartmut

2004-02-01

A thioredoxin-like chloroplast protein of the fructosebisphosphatase-stimulating f-type, but with an unusually high molecular mass of 28 kDa has previously been identified and purified to homogeneity in a fractionation scheme for resolution of the acid- and heat-stable, regular-size (12kDa) thioredoxins of the unicellular green algae, Scenedesmus obliquus. An apparently analogous protein of 26 kDa was described in a cyanobacterium, Anabaena sp., but no such large thioredoxin species f exists in the thioredoxin profiles of higher plants. The structure of the 28 kDa protein, which had been envisaged to represent a precursor, or fusion product of the two more specialized, common chloroplast thioredoxins f and m has now been determined by amino acid sequencing. Although it exhibits virtually all the properties and enzyme-modulating activities of a thioredoxin proper this algal protein, surprisingly, does not belong to the thioredoxin family of small redox proteins but is identical with OEE (oxygen evolving enhancer) protein 1, an auxiliary component of the photosystem II manganese cluster. Extracts of Chlorella vulgaris and Chlamydomonas reinhardtii also contain heat-stable protein fractions of 23-26 kDa capable of specifically stimulating chloroplast fructosebisphosphatase in vitro. In contrast, OEE protein 1 from spinach is not able to modulate FbPase or NADP malate dehydrogenase from spinach chloroplasts. A dual function of the OEE protein in algal photosynthesis is envisaged.

The Investigation of Strain-Induced Martensite Reverse Transformation in AISI 304 Austenitic Stainless Steel

NASA Astrophysics Data System (ADS)

Cios, G.; Tokarski, T.; Żywczak, A.; Dziurka, R.; Stępień, M.; Gondek, Ł.; Marciszko, M.; Pawłowski, B.; Wieczerzak, K.; Bała, P.

2017-10-01

This paper presents a comprehensive study on the strain-induced martensitic transformation and reversion transformation of the strain-induced martensite in AISI 304 stainless steel using a number of complementary techniques such as dilatometry, calorimetry, magnetometry, and in-situ X-ray diffraction, coupled with high-resolution microstructural transmission Kikuchi diffraction analysis. Tensile deformation was applied at temperatures between room temperature and 213 K (-60 °C) in order to obtain a different volume fraction of strain-induced martensite (up to 70 pct). The volume fraction of the strain-induced martensite, measured by the magnetometric method, was correlated with the total elongation, hardness, and linear thermal expansion coefficient. The thermal expansion coefficient, as well as the hardness of the strain-induced martensitic phase was evaluated. The in-situ thermal treatment experiments showed unusual changes in the kinetics of the reverse transformation (α' → γ). The X-ray diffraction analysis revealed that the reverse transformation may be stress assisted—strains inherited from the martensitic transformation may increase its kinetics at the lower annealing temperature range. More importantly, the transmission Kikuchi diffraction measurements showed that the reverse transformation of the strain-induced martensite proceeds through a displacive, diffusionless mechanism, maintaining the Kurdjumov-Sachs crystallographic relationship between the martensite and the reverted austenite. This finding is in contradiction to the results reported by other researchers for a similar alloy composition.

From Galaxies to the Intergalactic Medium

NASA Astrophysics Data System (ADS)

Peeples, Molly S.

2010-07-01

Deep in dark matter halos, galaxies are large factories that convert gas into stars. Gas is accreted from the expansive intergalactic medium (IGM); stars process this gas by fusing lighter elements into heavier ones. In this Dissertation, I combine both observations and theories from a variety of subfields of astrophysics with analytic and numerical models in an aim for a comprehensive understanding of the underlying physics of star formation feedback, galaxy chemical evolution, and the IGM. The mass-metallicity relation is an observed tight correlation between the stellar masses and gas-phase oxygen abundances of star-forming galaxies. I show that while the intrinsic scatter in this relation is small, extreme outliers do exist; I argue that these outliers have unusual metallicities for their masses because they have unusual gas fractions for their masses. The low-mass high-metallicity galaxies appear to be nearing the end of their star formation, and thus should have abnormally small gas reservoirs with which to dilute their metals. On the other hand, the high-mass low-metallicity galaxies appear to be undergoing gas-rich galaxy mergers, implying that they have larger-than-normal amounts of gas diluting their metals. I then show through analytic arguments that while gas fractions can have a large impact on observed metallicities, the low-redshift mass-metallicity relation is dominated by outflow properties because typical galaxies have relatively small gas fractions. Specifically, the mass-metallicity relation implies that the efficiency with which galaxies expel metals should scale steeply with galaxy mass. Combining this model with reasonable models for star formation feedback, I show that the outflow metallicity should likewise vary with galaxy mass; future measurements of wind metallicity can therefore inform models of the physics underlying galaxy winds. The high-redshift IGM is primarily observed through the Lyman-alpha absorption of neutral hydrogen along the line of sight to a distant quasar. As samples of close quasar pairs increase, so does the amount of potential information in the Lya forest transverse to the line-of-sight. Using two cosmological hydrodynamic simulations with different photoionization heating rates and thus different IGM temperature-density relations, I show that the small-scale structure in the Lya forest along the line of sight is dominated by the current thermal state of the gas. On the other hand, the transverse signal is sensitive to - and thus could be used to place unique constraints on - the thermal history of the gas. Finally, I investigate how a two-phase medium is treated in a suite of idealized smoothed particle hydrodynamic (SPH) simulations. I show that cold, dense spherical blobs become over-pressured relative to their hot, tenuous surroundings, arguing that this is because of an effective numerical surface tension owing to the un-resolveable density discontinuity. I then test one proposed modification to how pressure gradients are calculated in SPH, the so-called "relative pressure SPH" (rpSPH); while rpSPH leads to a more uniform pressure across the simulation, I show that it is ultimately unstable because of its lack of momentum conservation.

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.

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.

The Impact and Oxidation Survival of Selected Meteoritic Compounds: Signatures of Asteroid Organic Material on Planetary Surfaces

NASA Technical Reports Server (NTRS)

Cooper, George; Horz, Fred; Oleary, Alanna; Chang, Sherwood

2013-01-01

Polar, non-volatile organic compounds may be present on the surfaces (or near surfaces) of multiple Solar System bodies. If found, by current or future missions, it would be desirable to determine the origin(s) of such compounds, e.g., asteroidal or in situ. To test the possible survival of meteoritic compounds both during impacts with planetary surfaces and under subsequent (possibly) harsh ambient conditions, we subjected known meteoritic compounds to relatively high impact-shock pressures and/or to varying oxidizing/corrosive conditions. Tested compounds include sulfonic and phosphonic acids (S&P), polyaromatic hydrocarbons (PAHs) amino acids, keto acids, dicarboxylic acids, deoxy sugar acids, and hydroxy tricarboxylic acids (Table 1). Meteoritic sulfonic acids were found to be relatively abundant in the Murchison meteorite and to possess unusual S-33 isotope anomalies (non mass-dependent isotope fractionations). Combined with distinctive C-S and C-P bonds, the S&P are potential signatures of asteroidal organic material.

Biofilm architecture in a novel pressurized biofilm reactor.

PubMed

Jiang, Wei; Xia, Siqing; Duan, Liang; Hermanowicz, Slawomir W

2015-01-01

A novel pure-oxygen pressurized biofilm reactor was operated at different organic loading, mechanical shear and hydrodynamic conditions to understand the relationships between biofilm architecture and its operation. The ultimate goal was to improve the performance of the biofilm reactor. The biofilm was labeled with seven stains and observed with confocal laser scanning microscopy. Unusual biofilm architecture of a ribbon embedded between two surfaces with very few points of attachment was observed. As organic loading increased, the biofilm morphology changed from a moderately rough layer into a locally smoother biomass with significant bulging protuberances, although the chemical oxygen demand (COD) removal efficiency remained unchanged at about 75%. At higher organic loadings, biofilms contained a larger fraction of active cells distributed uniformly within a proteinaceous matrix with decreasing polysaccharide content. Higher hydrodynamic shear in combination with high organic loading resulted in the collapse of biofilm structure and a substantial decrease in reactor performance (a COD removal of 16%). Moreover, the important role of proteins for the spatial distribution of active cells was demonstrated quantitatively.

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.

Unusual void galaxy DDO 68: implications of the HST-resolved photometry

NASA Astrophysics Data System (ADS)

Makarov, D. I.; Makarova, L. N.; Pustilnik, S. A.; Borisov, S. B.

2017-04-01

DDO 68 (UGC 5340) is an unusual dwarf galaxy with extremely low gas metallicity [12 + log (O/H) = 7.14] residing in the nearby Lynx-Cancer void. Despite its apparent isolation, it shows both optical and H I morphological evidence for strong tidal disturbance. Here, we study the resolved stellar populations of DDO 68 using deep images from the HST archive. We determined a distance of 12.75 ± 0.41 Mpc using the tip of the red giant branch (TRGB). The star formation history reconstruction reveals that about 60 per cent of stars formed during the initial period of star formation, about 12-14 Gyr ago. During the next 10 Gyr, DDO 68 was in the quenched state, with only slight traces of star formation. The onset of the most recent burst of star formation occurred about 300 Myr ago. We find that young populations with ages of several million to a few hundred million years are widely spread across various parts of DDO 68, indicating an intense star formation episode with a high mean rate of 0.15 M⊙ yr-1. A major fraction of the visible stars in the whole system (˜80 per cent) have low metallicities: Z = Z⊙/50-Z⊙/20. The properties of the northern periphery of DDO 68 can be explained by an ongoing burst of star formation induced by the minor merger of a small, gas-rich, extremely metal-poor galaxy with a more typical dwarf galaxy. The current TRGB-based distance of DDO 68 implies a total negative peculiar velocity of ≈500 km s-1.

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.

Excited-state proton transfer dynamics of firefly's chromophore D-luciferin in DMSO-water binary mixture.

PubMed

Kuchlyan, Jagannath; Banik, Debasis; Roy, Arpita; Kundu, Niloy; Sarkar, Nilmoni

2014-12-04

In this article we have investigated intermolecular excited-state proton transfer (ESPT) of firefly's chromophore D-luciferin in DMSO-water binary mixtures using steady-state and time-resolved fluorescence spectroscopy. The unusual behavior of DMSO-water binary mixture as reported by Bagchi et al. (J. Phys. Chem. B 2010, 114, 12875-12882) was also found using D-luciferin as intermolecular ESPT probe. The binary mixture has given evidence of its anomalous nature at low mole fractions of DMSO (below XD = 0.4) in our systematic investigation. Upon excitation of neutral D-luciferin molecule, dual fluorescence emissions (protonated and deprotonated form) are observed in DMSO-water binary mixture. A clear isoemissive point in the time-resolved area normalized emission spectra further indicates two emissive species in the excited state of D-luciferin in DMSO-water binary mixture. DMSO-water binary mixtures of different compositions are fascinating hydrogen bonding systems. Therefore, we have observed unusual changes in the fluorescence emission intensity, fluorescence quantum yield, and fluorescence lifetime of more hydrogen bonding sensitive anionic form of D-luciferin in low DMSO content of DMSO-water binary mixture.

[Pheochromocytoma and cardiogenic failure: an indication for emergency adrenalectomy].

PubMed

Vandwalle, J; Spie, R; Jarry, G; Agaesse, V; Petit, J; Saint, F

2010-07-01

To identify cardiogenic failure or cardiogenic shock associated with pheochromocytoma diagnosis and emergency adrenalectomy. Update this unusual presentation of pheochromocytoma. Between 1998 and 2009, 119 adrenalectomies were performed in our department, among which 19 cases for pheochromocytoma. We reported three cases with cardiogenic failure or cardiogenic shock associated with emergency adrenalectomy. Patients were 36, 41 and 67 years old. The elapsed time between cardiogenic failure and surgery was 0, 7 and 19 days. The first diagnosis was a viral myocarditis in those three cases. The diagnosis of adrenal pheochromocytoma was done in a second step by the association of adrenal tumour on abdominal CT scan and detection of significantly elevated plasma/urine catecholamine. Severe systolic dysfunction with low ejection fraction was associated in all cases. Cardiac function was quickly restored after adrenalectomy. Cardiac emergency associated with pheochromocytoma is an unusual clinical presentation. When diagnosis fails to be performed, patients have a very poor prognosis. According to a review of the sparse literature, only early recognition and emergency adrenalectomy can improve the outcome. Copyright 2010. Published by Elsevier Masson SAS.

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.

Ar-39 - Ar-40 Dating of Unusual Eucrite NWA-011: Is it from Vesta?

NASA Technical Reports Server (NTRS)

Bogard, D. D.; Garrison, D. H.

2004-01-01

Basaltic meteorite NWA-011 is similar to eucrites in many aspects, but its oxygen isotopic composition lies far off the oxygen fractionation line defined by eucrites. It was suggested that NWA011 may have derived from a different parent body from that of eucrites, which are thought to derive from the asteroid Vesta. Some other eucrites also show small anomalous oxygen compositions. This suggests that for all eucrites to derive from Vesta, it must be compositionally inhomogeneous. Some workers have speculated whether early, large impactors on Vesta might have contributed the anomalous oxygen.

Emerging behavior in electronic bidding.

PubMed

Yang, I; Jeong, H; Kahng, B; Barabási, A-L

2003-07-01

We characterize the statistical properties of a large number of agents on two major online auction sites. The measurements indicate that the total number of bids placed in a single category and the number of distinct auctions frequented by a given agent follow power-law distributions, implying that a few agents are responsible for a significant fraction of the total bidding activity on the online market. We find that these agents exert an unproportional influence on the final price of the auctioned items. This domination of online auctions by an unusually active minority may be a generic feature of all online mercantile processes.

Emerging behavior in electronic bidding

NASA Astrophysics Data System (ADS)

Yang, I.; Jeong, H.; Kahng, B.; Barabási, A.-L.

2003-07-01

We characterize the statistical properties of a large number of agents on two major online auction sites. The measurements indicate that the total number of bids placed in a single category and the number of distinct auctions frequented by a given agent follow power-law distributions, implying that a few agents are responsible for a significant fraction of the total bidding activity on the online market. We find that these agents exert an unproportional influence on the final price of the auctioned items. This domination of online auctions by an unusually active minority may be a generic feature of all online mercantile processes.

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 ...

Nonspecific uptake and homeostasis drive the oceanic cadmium cycle

NASA Astrophysics Data System (ADS)

Horner, Tristan J.; Lee, Renee B. Y.; Henderson, Gideon M.; Rickaby, Rosalind E. M.

2013-02-01

The global marine distributions of Cd and phosphate are closely correlated, which has led to Cd being considered as a marine micronutrient, despite its toxicity to life. The explanation for this nutrient-like behavior is unknown because there is only one identified biochemical function for Cd, an unusual Cd/Zn carbonic anhydrase. Recent developments in Cd isotope mass spectrometry have revealed that Cd uptake by phytoplankton causes isotopic fractionation in the open ocean and in culture. Here we investigate the physiochemical pathways that fractionate Cd isotopes by performing subcellular Cd isotope analysis on genetically modified microorganisms. We find that expression of the Cd/Zn carbonic anhydrase makes no difference to the Cd isotope composition of whole cells. Instead, a large proportion of the Cd is partitioned into cell membranes with a similar direction and magnitude of Cd isotopic fractionation to that seen in surface seawater. This observation is well explained if Cd is mistakenly imported with other divalent metals and subsequently managed by binding within the cell to avoid toxicity. This process may apply to other divalent metals, whereby nonspecific uptake and subsequent homeostasis may contribute to elemental and isotopic distributions in seawater, even for elements commonly considered as micronutrients.

Axial high topography and partial melt in the crust and mantle beneath the western Galápagos Spreading Center

USGS Publications Warehouse

Blacic, Tanya M.; Ito, Garrett; Shah, Anjana K.; Canales, Juan Pablo; Lin, Jian

2008-01-01

The hot spot-influenced western Galápagos Spreading Center (GSC) has an axial topographic high that reaches heights of ∼700 m relative to seafloor depth ∼25 km from the axis. We investigate the cause of the unusual size of the axial high using a model that determines the flexural response to loads resulting from the thermal and magmatic structure of the lithosphere. The thermal structure simulated is appropriate for large amounts of cooling by hydrothermal circulation, which tends to minimize the amount of partial melt needed to explain the axial topography. Nonetheless, results reveal that the large axial high near 92°W requires that either the crust below the magma lens contains >35% partial melt or that 20% melt is present in the lower crust and at least 3% in the mantle within a narrow column (<∼10 km wide) extending to depths of 45–65 km. Because melt fractions >35% in the crust are considered unreasonable, it is likely that much of the axial high region of the GSC is underlain by a narrow region of partially molten mantle of widths approaching those imaged seismically beneath the East Pacific Rise. A narrow zone of mantle upwelling and melting, driven largely by melt buoyancy, is a plausible explanation.

Mechanism for starch granule ghost formation deduced from structural and enzyme digestion properties.

PubMed

Zhang, Bin; Dhital, Sushil; Flanagan, Bernadine M; Gidley, Michael J

2014-01-22

After heating in excess water under little or no shear, starch granules do not dissolve completely but persist as highly swollen fragile forms, commonly termed granule "ghosts". The macromolecular architecture of these ghosts has not been defined, despite their importance in determining characteristic properties of starches. In this study, amylase digestion of isolated granule ghosts from maize and potato starches is used as a probe to study the mechanism of ghost formation, through microstructural, mesoscopic, and molecular scale analyses of structure before and after digestion. Digestion profiles showed that neither integral nor surface proteins/lipids were crucial for control of either ghost digestion or integrity. On the basis of the molecular composition and conformation of enzyme-resistant fractions, it was concluded that the condensed polymeric surface structure of ghost particles is mainly composed of nonordered but entangled amylopectin (and some amylose) molecules, with limited reinforcement through partially ordered enzyme-resistant structures based on amylose (for maize starch; V-type order) or amylopectin (for potato starch; B-type order). The high level of branching and large molecular size of amylopectin is proposed to be the origin for the unusual stability of a solid structure based primarily on temporary entanglements.

Simultaneous increase in strength and ductility by decreasing interface energy between Zn and Al phases in cast Al-Zn-Cu alloy.

PubMed

Han, Seung Zeon; Choi, Eun-Ae; Park, Hyun Woong; Lim, Sung Hwan; Lee, Jehyun; Ahn, Jee Hyuk; Hwang, Nong-Moon; Kim, Kwangho

2017-09-22

Cast-Al alloys that include a high amount of the second element in their matrix have comparatively high strength but low ductility because of the high volume fraction of strengthening phases or undesirable inclusions. Al-Zn alloys that have more than 30 wt% Zn have a tensile strength below 300 MPa, with elongation under 5% in the as-cast state. However, we found that after substitution of 2% Zn by Cu, the tensile strength of as-cast Al-Zn-Cu alloys was 25% higher and ductility was four times higher than for the corresponding Al-35% Zn alloy. Additionally, for the Al-43% Zn alloy with 2% Cu after 1 h solution treatment at 400 °C and water quenching, the tensile strength unexpectedly reached values close to 600 MPa. For the Al-33% Zn alloy with 2% Cu, the tensile strength was 500 MPa with 8% ductility. The unusual trends of the mechanical properties of Al-Zn alloys with Cu addition observed during processing from casting to the subsequent solution treatment were attributed to the precipitation of Zn in the Al matrix. The interface energy between the Zn particles and the Al matrix decreased when using a solution of Cu in Zn.

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.

Biochemical profile of stone-forming patients with diabetes mellitus.

PubMed

Pak, Charles Y C; Sakhaee, Khashayar; Moe, Orson; Preminger, Glenn M; Poindexter, John R; Peterson, Roy D; Pietrow, Paul; Ekeruo, Wesley

2003-03-01

To test the hypothesis that stone-forming patients with type II diabetes (DM-II) have a high prevalence of uric acid (UA) stones and present with some of the biochemical features of gouty diathesis (GD). The demographic and initial biochemical data from 59 stone-forming patients with DM-II (serum glucose greater than 126 mg/dL, no insulin therapy, older than 35 years of age) from Dallas, Texas and Durham, North Carolina were retrieved and compared with data from 58 patients with GD and 116 with hyperuricosuric calcium oxalate urolithiasis (HUCU) without DM. UA stones were detected in 33.9% of patients with DM-II compared with 6.2% of stone-forming patients without DM (P <0.001). Despite similar ingestion of alkali, the urinary pH in patients with DM-II and UA stones (n = 20) was low (pH = 5.5), as it is in patients with GD, and was significantly lower than in patients with HUCU. The urinary pH in patients with DM-II and calcium stones (n = 39) was intermediate between that in those with DM-II and UA stones and those with HUCU. However, both DM groups had fractional excretion of urate that was not depressed, as it is in those with GD, and was comparable to the value obtained in those with HUCU. The urinary content of undissociated UA was significantly higher, and the saturation of calcium phosphate (brushite) and sodium urate was significantly lower in those with DM-II and UA stones than in those with HUCU. Stone-forming patients with DM-II have a high prevalence of UA stones. Diabetic patients with UA stones share a key feature of those with GD, namely the passage of unusually acid urine, but not the low fractional excretion of urate.

Association of Carbonic Anhydrase Activity with Carboxysomes Isolated from the Cyanobacterium Synechococcus PCC7942 1

PubMed Central

Price, G. Dean; Coleman, John R.; Badger, Murray R.

1992-01-01

The development of a simple method for the isolation of purified carboxysomes from the cyanobacterium Synechococcus PCC7942 has made it possible to identify a specific and inducible, intracellular carbonic anhydrase (CA) activity that is strongly associated with carboxysomes. This was shown, in part, through enzyme recovery experiments that indicated that a clear majority of a CA activity that is sensitive to the CA inhibitor ethoxyzolamide (I50 = 4 μm) copurifies with a majority of the cell's ribulose-1,5-bisphosphate carboxylase/oxygenase activity in a highly purified pelletable fraction. Electron microscopy of this pelletable fraction revealed the presence of carboxysomes that were physically intact. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of carboxysome proteins showed that the large and small subunits of ribulose-1,5-bisphosphate carbosylase/oxygenase were clearly prominent and that several other minor proteins could be distinguished. The specific location of this carboxysomal CA activity is further reinforced by the finding that a previously isolated high CO2-requiring mutant, Type II/No. 68 (G.D. Price, M.R. Badger [1989] Plant Physiol 91: 514-525), displayed a 30-fold reduction in carboxysome-associated CA activity when tested under optimal conditions. Carboxysomal CA has the unusual property of being inactivated by dithiothreitol. The enzyme also requires 20 mm Mg2+ (as MgSO4) for near maximum activity; other divalent cations, such as Ca2+ and Mn2+, also stimulate carboxysomal CA activity, but to a lesser extent than Mg2+. Results are discussed in relation to the role of carboxysomes in the CO2-concentrating mechanism in cyanobacteria and the role that carboxysomal CA activity appears to play in this process. Images Figure 1 Figure 7 PMID:16653059

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.

Prehistoric (Chalcolithic) Eastern Mediterranean tsunami deposit identified offshore central Israel

NASA Astrophysics Data System (ADS)

Tyuleneva, Natalia; Braun, Yael; Suchkov, Igor; Goodman-Tchernov, Beverly

2017-04-01

The shallow shelf area ( 15-30 m water depth) offshore Israel, bears great potential for paleo-tsunami studies. It was shown in the course of previous research that in these offshore marine deposits, tsunami generated sedimentary layers can be well preserved and readily identified; unlike in onshore sedimentary sequences, which experience continuous exogenous natural and anthropogenic influence. A sediment core, 219 cm long, was obtained from 15.3 m water depth, in about 4 km north of Caesarea. Grain size at 1 cm interval as well as XRD and XRF analyses at coarser resolution were performed. Previously carried out research allowed correlation of two anomalous layers in this core with well described sediment sequences offshore Caesarea. These two events correspond best with the proposed events of 749 AD and 1500 BC. Identified unusual layers in this core bear certain set of proxies that are characteristic for tsunami generated deposits and easily distinguished from the local normal marine setting. The latter is characterized by three dominating mineralogical components, such as carbonaceous sand derived either from biogenic material, namely shell fragments or from eroded limestones and dolomites that outcrop the mountains to the east; siliciclastic quartz for the sand fraction and mineral smectite for the clays. The supply of the two latter terrigenous sedimentary components comes from the Nile River, which has been a stable and predominant source of sediments for the past 8 ka. The aim of this study is to characterize the earliest unusual sedimentary layer found down core between 191 and 211 cm. This layer was attributed to a tsunami-generated sedimentary sequence in the studied core. Absolute age determination based on 14C gave the time frame from 5.6 to 6 ka BP, making this event the oldest identified in the Eastern Mediterranean to date. This tsunami corresponds to the Chalcolithic ('Copper Age') cultural period of the region. Prehistoric age of these sediments makes it impossible to correlate these identified tsunami generated sediments with any known tsunami or earthquake, since the event pre dates any written catalogues of the mentioned hazardous events. The results of this study allow to make following conclusions: (1) the unusual sedimentary layer carries indicators, characteristic for tsunami generated sediments in the studied core, such as distinct deviation of granulometric coefficients (mean, median, standard deviation, skewness, kurtosis) and presence of whole, imbricated bivalve mollusks shells; (2) the upper part of tsunami generated layer is characterized by increased content of illite, a characteristic clay mineral for terrestrial sediments; (3) increased content of heavy minerals and such elements as iron, titanium and zirconium at the top of the layer coincide with increased content of coarse sand fraction (541-1821 micron) suggesting deposition in high energy sedimentological setting and influence of a strong backwash wave, carrying terrestrial material to offshore marine environment.

Unusual very positive enrichment of 13C in carbonate sediments deposited in modern hypersaline environment, Lagoa Salgada, Brazil: Indicator of salinity controlled metabolic processes

NASA Astrophysics Data System (ADS)

McKenzie, J. A.; Bovier, C.; Bahniuk, A.; Andersen, M. B.; Vasconcelos, C.

2016-12-01

In the geologic record, prolonged intervals of intense δ13C enrichment (>10‰) in carbonate deposits occurred, in particular during the mid-Palaeoproterozoic (2.3-1.9 Ga) and mid-Neoproterozoic (0.8-0.6 Ga) [1]. These anomalously high δ13C values have been interpreted as a global effect due to enhanced burial of organic matter with depleted δ13C values [2]. An alternate interpretation has been proposed whereby the metabolic activity of specific microbial communities, such as methanogens, may have been the source of the strong carbon isotope fractionation [3]. Although such restricted shallow-water environments where methanogens dominate are not widespread today, a unique hypersaline coastal lagoon system, Lagoa Salgada, Brazil provides ideal conditions to study the modern microbial community and its impact on observed extreme δ13C enrichment (up to 20‰) recorded in both in situ stromatolites and carbonate sediments. Here we present our findings and correlations of geochemical data with changing environmental conditions during the last 2600 cal yr BP. This lagoonal system contains highly evaporated water with highest salinities occurring during the dry season. The positive δ13C anomaly shows high and stable values (>14‰) from about 2100 to 1400 cal yr BP. Similar high δ13C values were recorded for the same time period in stromatolite structures growing around the margin of Lagoa Salgada. We propose that the high salinities inhibit photosynthesis, respiration and nitrogen fixation by osmotic stress and, thus, result in increased methanogenesis. We conclude that the combination of methanogenic metabolisms and extreme evaporative conditions is the key factor promoting the production of very high δ13C values observed throughout the lagoonal system, as recorded in both marginal stromatolites and carbonate sediments deposited in the more distal regions of the lagoon. Such unusual environments may have been more widely distributed during the Proterozoic accounting for the intense δ13C enrichment (>10‰) observed in the sedimentary record. [1] Shields G and Veizer J (2002) Geochem. Geophys. Geosyst. 3(6): 10.1029 [2] Schidlowski M (1993) In: Organic Geochemistry: Plenum Press, 639-655 [3] Hayes JM and Waldbauer J Jr (2006) Philosophical Trans. Royal Soc. B Biological Sciences 361: 931-950

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.

Position-Dependent Dynamics Explain Pore-Averaged Diffusion in Strongly Attractive Adsorptive Systems.

PubMed

Krekelberg, William P; Siderius, Daniel W; Shen, Vincent K; Truskett, Thomas M; Errington, Jeffrey R

2017-12-12

Using molecular simulations, we investigate the relationship between the pore-averaged and position-dependent self-diffusivity of a fluid adsorbed in a strongly attractive pore as a function of loading. Previous work (Krekelberg, W. P.; Siderius, D. W.; Shen, V. K.; Truskett, T. M.; Errington, J. R. Connection between thermodynamics and dynamics of simple fluids in highly attractive pores. Langmuir 2013, 29, 14527-14535, doi: 10.1021/la4037327) established that pore-averaged self-diffusivity in the multilayer adsorption regime, where the fluid exhibits a dense film at the pore surface and a lower density interior pore region, is nearly constant as a function of loading. Here we show that this puzzling behavior can be understood in terms of how loading affects the fraction of particles that reside in the film and interior pore regions as well as their distinct dynamics. Specifically, the insensitivity of pore-averaged diffusivity to loading arises from the approximate cancellation of two factors: an increase in the fraction of particles in the higher diffusivity interior pore region with loading and a corresponding decrease in the particle diffusivity in that region. We also find that the position-dependent self-diffusivities scale with the position-dependent density. We present a model for predicting the pore-average self-diffusivity based on the position-dependent self-diffusivity, which captures the unusual characteristics of pore-averaged self-diffusivity in strongly attractive pores over several orders of magnitude.

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).

Petrogenesis of high-Ti and low-Ti basalts: high-pressure and high-temperature experimental study

NASA Astrophysics Data System (ADS)

Yang, J.; WANG, C.; Jin, Z.

2017-12-01

Geochemical and petrological studies have revealed the existence of high-Ti and low-Ti basalts in large igneous provinces. However, the petrogenesis of them are still under debate. Several different mechanisms have been proposed: (1) the high-Ti basalts are formed by the melting of mantle plume containing recycled oceanic crust or delaminated lower crust (Spandler et al., 2008) while low-Ti basalts are formed by the melting of subcontinental lithospheric mantle (Xiao et al., 2004); (2) both of them are from mantle plume or asthenospheric source, but the production of high-Ti basalts are associated with the thick lithosphere and relevant low degrees of melting while the low-Ti basalts are controlled by the thin lithosphere with high degrees of melting (Arndt et al., 1993; Xu et al., 2001). Almost all authors emphasize the role of partial melting but less discuss the crystallization differentiation process. The low Mg# (< 0.7) of these basalts provides that they are far away from direct melting of mantle peridotite. In addition, seismic data indicate unusually high seismic velocities bodies beneath LIPs which explained by the fractionated cumulates from picritic magmas (Farnetani et al., 1996). Therefore, we believed that the crystallization differentiation process might play a more significant role in the genesis of high-Ti and low-Ti basalts. In order to investigate the generation of these basalts, a series of high pressure and high temperature partial crystallization experiments were performed by using piston-cylinder and multi-anvil press at pressures of 1.5, 3.0 and 5.0 GPa and a temperature range of 1200-1700°. Two synthetic picrite glass with different chemical compositions were used as starting materials. Our experimental results show that Ti is preferred to be concentrated in the residual melt during crystallization differentiation. For the same melt fraction, the residual melt of higher pressure experiments has relatively higher TiO2 concentration and higher Mg#. Thus, we propose that most of the high-Ti and low-Ti basalts are inherited from picritic parental magmas which could be formed by high degree partial melting of garnet peridotite. The high-Ti basalts are generated through relatively high pressure crystallization process while the low-Ti basalts are generated at relatively low pressure.

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.

Polyprenols in leaves of fruit-trees of Rosaceae family.

PubMed

Swiezewska, E; Chojnacki, T

1996-01-01

In leaves of various species of fruit-trees belonging to the Rosaceae family, large amounts of polyprenyl acetates (0.5-5.0% of dry weight) were found. Discrete constant differences of polyprenol spectrum characteristic of each genus studied: Malus, Prunus and Pyrus were observed. In each species poly-cis-prenols composed of 19 and 20 isoprene units were predominating. In one of the 23 studied species (Prunus incisa) a fraction of long-chain polyprenols composed of 35-45 isoprene units was also present. It seems that this type of unusually long-chain polyprenols could occur also in other plants of the Rosaceae family.

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

Unusual broad-line Mg II emitters among luminous galaxies in the baryon oscillation spectroscopic survey

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

Roig, Benjamin; Blanton, Michael R.; Ross, Nicholas P.

2014-02-01

Many classes of active galactic nuclei (AGNs) have been observed and recorded since the discovery of Seyfert galaxies. In this paper, we examine the sample of luminous galaxies in the Baryon Oscillation Spectroscopic Survey. We find a potentially new observational class of AGNs, one with strong and broad Mg II λ2799 line emission, but very weak emission in other normal indicators of AGN activity, such as the broad-line Hα, Hβ, and the near-ultraviolet AGN continuum, leading to an extreme ratio of broad Hα/Mg II flux relative to normal quasars. Meanwhile, these objects' narrow-line flux ratios reveal AGN narrow-line regions withmore » levels of activity consistent with the Mg II fluxes and in agreement with that of normal quasars. These AGN may represent an extreme case of the Baldwin effect, with very low continuum and high equivalent width relative to typical quasars, but their ratio of broad Mg II to broad Balmer emission remains very unusual. They may also be representative of a class of AGN where the central engine is observed indirectly with scattered light. These galaxies represent a small fraction of the total population of luminous galaxies (≅ 0.1%), but are more likely (about 3.5 times) to have AGN-like nuclear line emission properties than other luminous galaxies. Because Mg II is usually inaccessible for the population of nearby galaxies, there may exist a related population of broad-line Mg II emitters in the local universe which is currently classified as narrow-line emitters (Seyfert 2 galaxies) or low ionization nuclear emission-line regions.« 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…

Flux of particulate matter through copepods in the Northeast water polynya

NASA Astrophysics Data System (ADS)

Daly, Kendra L.

1997-01-01

Particulate organic carbon (POC) and nitrogen (PON) production by large calanoid copepods was investigated on the northeast Greenland shelf during August 1992 and May to August 1993. Both Calanus hyperboreus and C. glacialis females, when suspended in seawater collected from the chlorophyll maximum, produced about 40 pellets per day, which contained a carbon and nitrogen content equivalent to 8% and 6% of body carbon, respectively, and 2% of body nitrogen. In experiments, the carbon:nitrogen (C:N) ratio by weight of suspended particulates, C. hyperboreus, and fecal pellets was 6.7, 7.7 and 28.5, respectively. The unusually high C:N ratio for pellets, in part, may be attributed to elevated ratios of > 20μm size fractions of particulate organic matter, the size fraction more common in the diet of these large copepods and the fraction dominated by diatoms according to microscopic and pigment data. The implied elevated C:N ratios of large phytoplankton cells were probably due to nitrogen deficiency, as shown by other studies in this region. In addition, female C. hyperboreus appeared to be more efficient in assimilating nitrogen than carbon, which also would have contributed to high C:N ratios in egested pellets. Unfractionated POC concentrations explained 54% of the variability in carbon egestion and 70% of the variability in nitrogen egestion in copepods, whereas copepod body content accounted for little of the variation on the short time scales of the experiments. Carbon egestion by C. hyperboreus was positively correlated with POC concentrations at the depth of the chlorophyll maximum, while nitrogen egestion was negatively correlated with PON concentrations in the euphotic zone. Estimates of potential community egestion rates for the upper water column indicate that copepods represent a major pathway of organic carbon transformation in this Arctic shelf system. On average, copepods may have ingested 45% of the primary production and egested fecal matter equivalent to 20% of the carbon and 12% of the nitrogen particulate flux sedimenting from the surface layer. However, several lines of evidence suggest that pellets were remineralized in the water column and, hence, may have contributed little organic carbon and nitrogen to the benthos.

The unreasonable effectiveness of my self-experimentation.

PubMed

Roberts, Seth

2010-12-01

Over 12 years, my self-experimentation found new and useful ways to improve sleep, mood, health, and weight. Why did it work so well? First, my position was unusual. I had the subject-matter knowledge of an insider, the freedom of an outsider, and the motivation of a person with the problem. I did not need to publish regularly. I did not want to display status via my research. Second, I used a powerful tool. Self-experimentation about the brain can test ideas much more easily (by a factor of about 500,000) than conventional research about other parts of the body. When you gather data, you sample from a power-law-like distribution of progress. Most data helps a little; a tiny fraction of data helps a lot. My subject-matter knowledge and methodological skills (e.g., in data analysis) improved the distribution from which I sampled (i.e., increased the average amount of progress per sample). Self-experimentation allowed me to sample from it much more often than conventional research. Another reason my self-experimentation was unusually effective is that, unlike professional science, it resembled the exploration of our ancestors, including foragers, hobbyists, and artisans. Copyright © 2010 Elsevier Ltd. All rights reserved.

Isochronal annealing effects on local structure, crystalline fraction, and undamaged region size of radiation damage in Ga-stabilized δ-Pu

DOE PAGES

Olive, D. T.; Booth, C. H.; Wang, D. L.; ...

2016-07-19

The effects on the local structure due to self-irradiation damage of Ga stabilized δ-Pu stored at cryogenic temperatures have been examined using extended x-ray absorption fine structure (EXAFS) experiments. Extensive damage, seen as a loss of local order, was evident after 72 days of storage below 15 K. The effect was observed from both the Pu and the Ga sites, although less pronounced around Ga. Isochronal annealing was performed on this sample to study the annealing processes that occur between cryogenic and room temperature storage conditions, where damage is mostly reversed. Damage fractions at various points along the annealing curvemore » have been determined using an amplitude-ratio method, a standard EXAFS fitting, and a spherical crystallite model, and provide information complementary to the previous electrical resistivity- and susceptibility-based isochronal annealing studies. The use of a spherical crystallite model accounts for the changes in EXAFS spectra using just two parameters, namely, the crystalline fraction and the particle radius. Altogether, these results are discussed in terms of changes to the local structure around Ga and Pu throughout the annealing process and highlight the unusual role of Ga in the behavior of the lowest temperature anneals.« less

Isochronal annealing effects on local structure, crystalline fraction, and undamaged region size of radiation damage in Ga-stabilized δ-Pu

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

Olive, D. T.; Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545; Wang, D. L.

2016-07-21

The effects on the local structure due to self-irradiation damage of Ga stabilized δ-Pu stored at cryogenic temperatures have been examined using extended x-ray absorption fine structure (EXAFS) experiments. Extensive damage, seen as a loss of local order, was evident after 72 days of storage below 15 K. The effect was observed from both the Pu and the Ga sites, although less pronounced around Ga. Isochronal annealing was performed on this sample to study the annealing processes that occur between cryogenic and room temperature storage conditions, where damage is mostly reversed. Damage fractions at various points along the annealing curve havemore » been determined using an amplitude-ratio method, a standard EXAFS fitting, and a spherical crystallite model, and provide information complementary to the previous electrical resistivity- and susceptibility-based isochronal annealing studies. The use of a spherical crystallite model accounts for the changes in EXAFS spectra using just two parameters, namely, the crystalline fraction and the particle radius. Together, these results are discussed in terms of changes to the local structure around Ga and Pu throughout the annealing process and highlight the unusual role of Ga in the behavior of the lowest temperature anneals.« less

Solvatochromism and preferential solvation of 1,4-dihydroxy-2,3-dimethyl-9,10-anthraquinone by UV-vis absorption and laser-induced fluorescence measurements

NASA Astrophysics Data System (ADS)

Sasirekha, V.; Vanelle, P.; Terme, T.; Ramakrishnan, V.

2008-12-01

Solvation characteristics of 1,4-dihydroxy-2,3-dimethyl-9,10-anthraquinone ( 1) in pure and binary solvent mixtures have been studied by UV-vis absorption spectroscopy and laser-induced fluorescence techniques. The binary solvent mixtures used as CCl 4 (tetrachloromethane)-DMF ( N, N-dimethylformamide), AN (acetonitrile)-DMSO (dimethylsulfoxide), CHCl 3 (chloroform)-DMSO, CHCl 3-MeOH (methanol), and MeOH-DMSO. The longest wavelength band of 1 has been studied in pure solvents as well as in binary solvent mixtures as a function of the bulk mole fraction. The Vis absorption band maxima show an unusual blue shift with increasing solvent polarity. The emission maxima of 1 show changes with varying the pure solvents and the composition in the case of binary solvent mixtures. Non-ideal solvation characteristics are observed in all binary solvent mixtures. It has been observed that the quantity [ ν-(Xν+Xν)] serves as a measure of the extent of preferential solvation, where ν˜ and X are the position of band maximum in wavenumbers (cm -1) and the bulk mole fraction values, respectively. The preferential solvation parameters local mole fraction ( X2L), solvation index ( δs2), and exchange constant ( k12) are evaluated.

Centennial and Extreme Climate Variability in the Last 1500 Year from the Belize Central Shelf Lagoon (Central America): Successive Droughts and Floods Linked to the Demise of the Mayan Civilization

NASA Astrophysics Data System (ADS)

Droxler, A. W.; Agar Cetin, A.; Bentley, S. J.

2014-12-01

This study focuses on the last 1500 yr precipitation record archived in the mixed carbonate/siliciclastic sediments accumulated in the Belize Central Shelf Lagoon, part of the Yucatan Peninsula eastern continental margin, proximal to the land areas where the Mayan Civilization thrived and then abruptly collapsed. This study is mainly based upon the detailed analyses of cores, BZE-RH-SVC-58 and 68, retrieved in 30 and 19 m of water depth from Elbow Caye Lagoon and English Caye Channel, respectively. The core timeframe is well-constrained by AMS radiocarbon dating of benthic foraminifera, Quinqueloculina. Carbonate content was determined by carbonate bomb, particle size fractions with a Malvern Master Sizer 2000 particle size analyzer, and element (Ti, Si, K, Fe, Al, Ca, and Sr) counts via X-Ray Fluorescence (XRF). The variations of elements such as Ti and K counts, and Ti/Al in these two cores have recorded, in the past past 1500 years, the weathering rate variations of the adjacent Maya Mountain, defining alternating periods of high precipitation and droughts, linked to large climate fluctuations and extreme events, highly influenced by the ITCZ latitudinal migration. The CE 800-900 century just preceding the Medieval Climate Anomaly (MCA), characterized by unusually low Ti counts and Ti/Al, is interpreted to represent a time of low precipitation and resulting severe droughts in the Yucatan Peninsula, contemporaneous with the Mayan Terminal Classic Collapse. High Ti counts and Ti/Al, although highly variable, during the MCA (CE 900-1350) are interpreted as an unusually warm period characterized by two 100-to-250 years-long intervals of higher precipitation when the number of tropical cyclones peaked. These two intervals of high precipitation during the MCA are separated by a century (CE 1000 -1100) of severe droughts and low tropical storm frequency coinciding with the collapse of Chichen Itza (CE 1040-1100). The Little Ice Age (CE 1350-1850), several centuries during which Ti counts and Ti/Al reach minimum values, is characterized by systematic drier and colder climate conditions with low frequency of tropical cyclones. Two extreme Ti and K count minima might coincide with historical drought times and related Caribbean-wide famines in the year CE 1535 and the last third of the 18th century (CE 1765-1800).

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).

High-order fractional partial differential equation transform for molecular surface construction.

PubMed

Hu, Langhua; Chen, Duan; Wei, Guo-Wei

2013-01-01

Fractional derivative or fractional calculus plays a significant role in theoretical modeling of scientific and engineering problems. However, only relatively low order fractional derivatives are used at present. In general, it is not obvious what role a high fractional derivative can play and how to make use of arbitrarily high-order fractional derivatives. This work introduces arbitrarily high-order fractional partial differential equations (PDEs) to describe fractional hyperdiffusions. The fractional PDEs are constructed via fractional variational principle. A fast fractional Fourier transform (FFFT) is proposed to numerically integrate the high-order fractional PDEs so as to avoid stringent stability constraints in solving high-order evolution PDEs. The proposed high-order fractional PDEs are applied to the surface generation of proteins. We first validate the proposed method with a variety of test examples in two and three-dimensional settings. The impact of high-order fractional derivatives to surface analysis is examined. We also construct fractional PDE transform based on arbitrarily high-order fractional PDEs. We demonstrate that the use of arbitrarily high-order derivatives gives rise to time-frequency localization, the control of the spectral distribution, and the regulation of the spatial resolution in the fractional PDE transform. Consequently, the fractional PDE transform enables the mode decomposition of images, signals, and surfaces. The effect of the propagation time on the quality of resulting molecular surfaces is also studied. Computational efficiency of the present surface generation method is compared with the MSMS approach in Cartesian representation. We further validate the present method by examining some benchmark indicators of macromolecular surfaces, i.e., surface area, surface enclosed volume, surface electrostatic potential and solvation free energy. Extensive numerical experiments and comparison with an established surface model indicate that the proposed high-order fractional PDEs are robust, stable and efficient for biomolecular surface generation.

Record of archaeal activity at the serpentinite-hosted Lost City Hydrothermal Field.

PubMed

Méhay, S; Früh-Green, G L; Lang, S Q; Bernasconi, S M; Brazelton, W J; Schrenk, M O; Schaeffer, P; Adam, P

2013-11-01

Samples of young, outer surfaces of brucite-carbonate deposits from the ultramafic-hosted Lost City hydrothermal field were analyzed for DNA and lipid biomarker distributions and for carbon and hydrogen stable isotope compositions of the lipids. Methane-cycling archaeal communities, notably the Lost City Methanosarcinales (LCMS) phylotype, are specifically addressed. Lost City is unlike all other hydrothermal systems known to date and is characterized by metal- and CO2 -poor, high pH fluids with high H2 and CH4 contents resulting from serpentinization processes at depth. The archaeal fraction of the microbial community varies widely within the Lost City chimneys, from 1-81% and covaries with concentrations of hydrogen within the fluids. Archaeal lipids include isoprenoid glycerol di- and tetraethers and C25 and C30 isoprenoid hydrocarbons (pentamethylicosane derivatives - PMIs - and squalenoids). In particular, unsaturated PMIs and squalenoids, attributed to the LCMS archaea, were identified for the first time in the carbonate deposits at Lost City and probably record processes exclusively occurring at the surface of the chimneys. The carbon isotope compositions of PMIs and squalenoids are remarkably heterogeneous across samples and show highly (13) C-enriched signatures reaching δ(13) C values of up to +24.6‰. Unlike other environments in which similar structural and isotopic lipid heterogeneity has been observed and attributed to diversity in the archaeal assemblage, the lipids here appear to be synthesized solely by the LCMS. Some of the variations in lipid isotope signatures may, in part, be due to unusual isotopic fractionation during biosynthesis under extreme conditions. However, we argue that the diversity in archaeal abundances, lipid structure and carbon isotope composition rather reflects the ability of the LCMS archaeal biofilms to adapt to chemical gradients in the hydrothermal chimneys and possibly to perform either methanotrophy or methanogenesis using dissolved inorganic carbon, methane or formate as a function of the prevailing environmental conditions. © 2013 John Wiley & Sons Ltd.

Multiple age components in individual molybdenite grains

USGS Publications Warehouse

Aleinikoff, John N.; Creaser, Robert A.; Lowers, Heather; Magee, Charles W.; Grauch, Richard I.

2012-01-01

Re–Os geochronology of fractions composed of unsized, coarse, and fine molybdenite from a pod of unusual monazite–xenotime gneiss within a granulite facies paragneiss, Hudson Highlands, NY, yielded dates of 950.5 ± 2.5, 953.8 ± 2.6, and 941.2 ± 2.6 Ma, respectively. These dates are not recorded by co-existing zircon, monazite, or xenotime. SEM–BSE imagery of thin sections and separated grains reveals that most molybdenite grains are composed of core and rim plates that are approximately perpendicular. Rim material invaded cores, forming irregular contacts, probably reflecting dissolution/reprecipitation. EPMA and LA-ICP-MS analyses show that cores and rims have different trace element concentrations (for example, cores are relatively enriched in W). On the basis of inclusions of zircon with metamorphic overgrowths, we conclude that molybdenite cores and rims formed after high-grade regional metamorphism. The discovery of cores and rims in individual molybdenite grains is analogous to multi-component U-Pb geochronometers such as zircon, monazite, and titanite; thus, molybdenite should be carefully examined before dating to ensure that the requirement of age homogeneity is fulfilled.

REE partitioning between apatite and melt in a peralkaline volcanic suite, Kenya Rift Valley

USGS Publications Warehouse

Macdonald, R.; Baginski, B.; Belkin, H.E.; Dzierzanowski, P.; Jezak, L.

2009-01-01

Electron microprobe analyses are presented for fluorapatite phenocrysts from a benmoreite-peralkaline rhyolite volcanic suite from the Kenya Rift Valley. The rocks have previously been well characterized petrographically and their crystallization conditions are reasonably well known. The REE contents in the M site increase towards the rhyolites, with a maximum britholite component of ~35 mol.%. Chondrite-normalized REE patterns are rather flat between La and Sm and then decrease towards Yb. Sodium and Fe occupy up to 1% and 4%, respectively, of the M site. The major coupled substitution is REE3+ + Si4+ ??? Ca2+ + P5+. The substitution REE3+ + Na+ ??? 2Ca2+ has been of minor importance. The relatively large Fe contents were perhaps facilitated by the low fo2 conditions of crystallization. Zoning is ubiquitous and resulted from both fractional crystallization and magma mixing. Apatites in some rhyolites are relatively Y-depleted, perhaps reflecting crystallization from melts which had precipitated zircon. Mineral/glass (melt) ratios for two rhyolites are unusually high, with maxima at Sm (762, 1123). ?? 2008 The Mineralogical Society.

Ultra-robust high-field magnetization plateau and supersolidity in bond-frustrated MnCr2S4

PubMed Central

Tsurkan, Vladimir; Zherlitsyn, Sergei; Prodan, Lilian; Felea, Viorel; Cong, Pham Thanh; Skourski, Yurii; Wang, Zhe; Deisenhofer, Joachim; von Nidda, Hans-Albrecht Krug; Wosnitza, Joahim; Loidl, Alois

2017-01-01

Frustrated magnets provide a promising avenue for realizing exotic quantum states of matter, such as spin liquids and spin ice or complex spin molecules. Under an external magnetic field, frustrated magnets can exhibit fractional magnetization plateaus related to definite spin patterns stabilized by field-induced lattice distortions. Magnetization and ultrasound experiments in MnCr2S4 up to 60 T reveal two fascinating features: (i) an extremely robust magnetization plateau with an unusual spin structure and (ii) two intermediate phases, indicating possible realizations of supersolid phases. The magnetization plateau characterizes fully polarized chromium moments, without any contributions from manganese spins. At 40 T, the middle of the plateau, a regime evolves, where sound waves propagate almost without dissipation. The external magnetic field exactly compensates the Cr–Mn exchange field and decouples Mn and Cr sublattices. In analogy to predictions of quantum lattice-gas models, the changes of the spin order of the manganese ions at the phase boundaries of the magnetization plateau are interpreted as transitions to supersolid phases. PMID:28345038

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

High-order fractional partial differential equation transform for molecular surface construction

PubMed Central

Hu, Langhua; Chen, Duan; Wei, Guo-Wei

2013-01-01

Fractional derivative or fractional calculus plays a significant role in theoretical modeling of scientific and engineering problems. However, only relatively low order fractional derivatives are used at present. In general, it is not obvious what role a high fractional derivative can play and how to make use of arbitrarily high-order fractional derivatives. This work introduces arbitrarily high-order fractional partial differential equations (PDEs) to describe fractional hyperdiffusions. The fractional PDEs are constructed via fractional variational principle. A fast fractional Fourier transform (FFFT) is proposed to numerically integrate the high-order fractional PDEs so as to avoid stringent stability constraints in solving high-order evolution PDEs. The proposed high-order fractional PDEs are applied to the surface generation of proteins. We first validate the proposed method with a variety of test examples in two and three-dimensional settings. The impact of high-order fractional derivatives to surface analysis is examined. We also construct fractional PDE transform based on arbitrarily high-order fractional PDEs. We demonstrate that the use of arbitrarily high-order derivatives gives rise to time-frequency localization, the control of the spectral distribution, and the regulation of the spatial resolution in the fractional PDE transform. Consequently, the fractional PDE transform enables the mode decomposition of images, signals, and surfaces. The effect of the propagation time on the quality of resulting molecular surfaces is also studied. Computational efficiency of the present surface generation method is compared with the MSMS approach in Cartesian representation. We further validate the present method by examining some benchmark indicators of macromolecular surfaces, i.e., surface area, surface enclosed volume, surface electrostatic potential and solvation free energy. Extensive numerical experiments and comparison with an established surface model indicate that the proposed high-order fractional PDEs are robust, stable and efficient for biomolecular surface generation. PMID:24364020

High-Ca Boninites From the Modern Tonga Arc

NASA Astrophysics Data System (ADS)

Cooper, L. B.; Plank, T.; Arculus, R. J.; Hauri, E. H.; Worthington, T. J.

2007-12-01

High-Ca boninites are volcanic rocks with unusual compositions (SiO2>53 wt%, Mg#>0.6, CaO/Al2O3>0.75) found in forearcs and trenches, continental cratons, and ophiolites. Generation of high-Ca boninites requires a combination of refractory mantle sources, elevated mantle temperatures and the addition of hydrous fluids. To satisfy these conditions, petrogenetic models invoke unusual tectonic settings such as subduction initiation, ridge subduction, or mantle plume interaction. We have discovered high-Ca boninites from an active arc volcano, Volcano A, a submarine volcano in the Tonga arc dredged during the NoToVE cruise in Nov 2004. Multi-beam sonar images of two pristine volcanic cones and glassy samples lacking Mn coatings suggest that these edifices were formed by modern volcanism. The boninites are represented in both the whole rock and melt inclusion populations of a sample dredged from a ridge on the northern flank of the northern cone. Similarities in the major element compositions of the largely aphyric whole rock and the glassy melt inclusions support both as samples of true boninitic liquids (MgO>9 wt%). These liquids are related by coupled crystal fractionation (from Fo92 to Fo85 in olivine hosts) and degassing (from 4 to 1 wt% H2O in the melt inclusions). Three other dredges from Volc A include whole rocks, glass, and melt inclusions that are related to the boninites by crystal fractionation. Taken together, the samples from Volc A represent a suite of boninites and their differentiates, forming a coherent liquid line of descent with parallel whole rock REE patterns which become more enriched with decreasing Mg#. The REE patterns for Volc A whole rocks are depleted in LREE, however, in contrast to the characteristic U-shaped REE patterns of classic boninites. Volc A is only the second example of boninites being erupted in an active volcanic arc, the first being Bamus volcano in New Britain (Johnson et al., Geol. Rund., 1983). Volc A is not remarkable in its geographical setting, located in the central portion of the Tonga arc, at around 21°S, along-strike with the arc island of Hunga- Ha'apai, and east of the Eastern Lau Spreading Center. Although it contains volcanic rocks with the highest Ba/La (100-130), Si6.00 (56 wt%) and lowest Ti6.00 (0.44 wt%) in the Tonga arc, Volc A forms an end- member within a continuous spectrum of compositions, and much of the Tonga arc appears to have boninite- affinities. Of the three conditions that promote boninite production (mantle depletion, high mantle temperatures, and high mantle water contents), we can exclude mantle temperature as the primary cause of Volc A boninites. Olivine-liquid temperatures are 1348±13°C for Volc A liquids, calculated in equilibrium with Fo92 mantle olivine at 2 GPa (using thermometers in Sisson & Grove, CMP, 1993; Sugawara, JGR, 2000). Such temperatures are very similar to those calculated for Central American arc volcanoes (1315-1320°C; Plank et al., this meeting) where magmas with similar water contents erupt, but boninites do not. Volc A olivine-liquid temperatures also contrast with those recorded in the high-Ca boninites found in the Tonga forearc (~1480°C; Falloon and Danyushevsky, JPet, 2000). Thus, we attribute the presence of boninites in the Tonga arc to the remelting of refractory mantle that melted previously during rapid back-arc spreading in the nearby Lau Basin.

Negative and Zero Thermal Expansion NiTi Superelastic Shape Memory Alloy by Microstructure Engineering

NASA Astrophysics Data System (ADS)

Sun, Qingping; Yu, Chao; Kang, Guozheng

2018-03-01

We report recent progress in tailoring the thermal expansion (TE) of nanocrystalline (NC) NiTi by microstructure hierarchical design and control without composition change. Fabrication and characterization methods are outlined and preliminary results of both experiment and mechanism-based modeling are presented to understand and get insight into the unusual TE phenomena. The important roles of the intrinsic thermal expansion anisotropy of B19' lattice and the suppression of phase transition by the extrinsic fabricated microstructure (cold rolling and annealing, grain size, defects, textures and volume fractions of nanoscaled B2 and B19' lattices) in the overall macroscopic TE behaviors of the superelastic NC NiTi polycrystal SMAs are emphasized.

Hypercalcemic crisis and primary hyperparathyroidism: Cause of an unusual electrical storm.

PubMed

Guimarães, Tatiana; Nobre Menezes, Miguel; Cruz, Diogo; do Vale, Sónia; Bordalo, Armando; Veiga, Arminda; Pinto, Fausto J; Brito, Dulce

2017-12-01

Hypercalcemia is a known cause of heart rhythm disorders, however its association with ventricular arrhythmias is rare. The authors present a case of a fifty-three years old male patient with a ischemic and ethanolic dilated cardiomyopathy, and severely reduced ejection fraction, carrier of cardiac resynchronization therapy (CRT) with cardioverter defibrillator (ICD), admitted in the emergency department with an electrical storm, with multiple appropriated ICD shocks, refractory to antiarrhythmic therapy. In the etiological investigation was documented severe hypercalcemia secondary to primary hyperparathyroidism undiagnosed until then. Only after the serum calcium level reduction ventricular tachycardia was stopped. Copyright © 2017 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Petrologic and Chemical Characterization of a Suite of Antarctic Diogenites

NASA Technical Reports Server (NTRS)

Mittlefehldt, D. W.; Mertzman, S. A.; Peng, Z. X.; Mertzman, K. R.

2013-01-01

The origin of diogenites, ultramafic cumulates related to eucrites, is an unresolved problem [1]. Most diogenites are orthopyroxenites, a few are harzburgites [2], and some are transitional to cumulate eucrites [1, 3]. Cumulate eucrites are gabbros formed by crystal fractionation from basaltic eucrites [4]. The consensus view is that basaltic eucrites are residual melts from global-magma-ocean crystallization on their parent asteroid [4] which is plausibly Vesta [5]. However, the petrologic and compositional characteristics of diogenites seem to preclude a magma ocean origin [1, 4]. We are doing a petrologic and chemical study of new or unusual diogenites with the ultimate goals of constraining their genesis, and the geologic evolution of Vesta.

Bioactive annonaceous acetogenins from the bark of Xylopia aromatica.

PubMed

Colman-Saizarbitoria, T; Zambrano, J; Ferrigni, N R; Gu, Z M; Ng, J H; Smith, D L; McLaughlin, J L

1994-04-01

Bioactive Annonaceous acetogenins have been isolated from the EtOH extract of the bark of Xylopia aromatica by bioactivity-directed fractionation using lethality to brine shrimp. These acetogenins include xylopianin [1 , xylopiacin [2], and xylomaticin [3], which are three new mono-tetrahydrofuran ring type acetogenins, in addition to the known compounds, annomontacin, gigantetronenin, gigantetrocin A, and annonacin. Compounds 1 and 2 are unusual in having hydroxylation at C-8; 3 has the same functionalities as annonacin but with 37 carbons instead of 35 carbons. The structures were elucidated by spectral analysis of the parent compounds and/or simple chemical derivatives. These acetogenins showed cytotoxicities, comparable to adriamycin, against three human solid tumor cell lines.

Evidence for marine origin and microbial-viral habitability of sub-zero hypersaline aqueous inclusions within permafrost near Barrow, Alaska.

PubMed

Colangelo-Lillis, J; Eicken, H; Carpenter, S D; Deming, J W

2016-05-01

Cryopegs are sub-surface hypersaline brines at sub-zero temperatures within permafrost; their global extent and distribution are unknown. The permafrost barrier to surface and groundwater advection maintains these brines as semi-isolated systems over geological time. A cryopeg 7 m below ground near Barrow, Alaska, was sampled for geochemical and microbiological analysis. Sub-surface brines (in situtemperature of -6 °C, salinity of 115 ppt), and an associated sediment-infused ice wedge (melt salinity of 0.04 ppt) were sampled using sterile technique. Major ionic concentrations in the brine corresponded more closely to other (Siberian) cryopegs than to Standard seawater or the ice wedge. Ionic ratios and stable isotope analysis of water conformed to a marine or brackish origin with subsequent Rayleigh fractionation. The brine contained ∼1000× more bacteria than surrounding ice, relatively high viral numbers suggestive of infection and reproduction, and an unusually high ratio of particulate to dissolved extracellular polysaccharide substances. A viral metagenome indicated a high frequency of temperate viruses and limited viral diversity compared to surface environments, with closest similarity to low water activity environments. Interpretations of the results underscore the isolation of these underexplored microbial ecosystems from past and present oceans. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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.

CO2 jets formed by sublimation beneath translucent slab ice in Mars' seasonal south polar ice cap

USGS Publications Warehouse

Kieffer, H.H.; Christensen, P.R.; Titus, T.N.

2006-01-01

The martian polar caps are among the most dynamic regions on Mars, growing substantially in winter as a significant fraction of the atmosphere freezes out in the form of CO2 ice. Unusual dark spots, fans and blotches form as the south-polar seasonal CO2 ice cap retreats during spring and summer. Small radial channel networks are often associated with the location of spots once the ice disappears. The spots have been proposed to be simply bare, defrosted ground; the formation of the channels has remained uncertain. Here we report infrared and visible observations that show that the spots and fans remain at CO2 ice temperatures well into summer, and must be granular materials that have been brought up to the surface of the ice, requiring a complex suite of processes to get them there. We propose that the seasonal ice cap forms an impermeable, translucent slab of CO2 ice that sublimates from the base, building up high-pressure gas beneath the slab. This gas levitates the ice, which eventually ruptures, producing high-velocity CO 2 vents that erupt sand-sized grains in jets to form the spots and erode the channels. These processes are unlike any observed on Earth. ?? 2006 Nature Publishing Group.

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.

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.

Novel peptides from adrenomedullary chromaffin vesicles.

PubMed Central

Sigafoos, J; Chestnut, W G; Merrill, B M; Taylor, L C; Diliberto, E J; Viveros, O H

1993-01-01

The adrenal medulla chromaffin vesicle (CV) contains, on a weight basis, as much soluble protein and peptide as catecholamine. The bulk of the protein is accounted for by chromogranins (Cgr) A, B and C. Additionally, a large variety of neuropeptides and their precursor proteins have been found recently within these vesicles. Nevertheless, fractionation of CV lysates indicates the presence of many more peptides than previously reported. In the hope of finding novel bioactive peptides, we initiated a systematic isolation and characterisation of CV peptides. Bovine CV pellets were prepared by sucrose gradient centrifugation and immediately boiled in water to avoid degradation of native proteins and peptides. The water lysates were fractionated through a battery of reversed-phase and ion-exchange high-performance chromatographic steps. We fully or partially characterised a substantial number of novel peptides derived from CgrA and CgrB. A tetradecapeptide and a 13 kDa extended peptide were derived from the bovine homologue of rat secretogranin III. Peptides corresponding to C-terminal fragments of 7B2 and proteoglycan II were also found. Additionally, several sequences had no known precursors. Of the sequences derived from known precursors some corresponded to fragments bracketed by pairs of basic amino acids, but others were preceded or followed by single basic residues or by unusual putative cleavage sites. Some of these peptides were postranslationally modified (pyroglutamylation, glycosylation, phosphorylation, amidation). A significant degree of structural conservation of some of these peptides across species suggests that they may exert biological effects when cosecreted with catecholamines during splanchnic stimulation. PMID:8300415

Silurian/Ordovician asymmetrical sill-like bodies from La Codosera syncline, W Spain: A case of tholeiitic partial melts emplaced in a single magma pulse and derived from a metasomatized mantle source

NASA Astrophysics Data System (ADS)

López-Moro, F. J.; Murciego, A.; López-Plaza, M.

2007-07-01

A Silurian/Ordovician extensional event in the southernmost sectors of the Central Iberian Zone is inferred from the Sm/Nd isochron obtained (436 ± 17 Ma) after the diabase sills from the La Codosera syncline. From the geochemical and mineralogical points of view, the diabase sills are subalkaline and range between high-Mg tholeiite diabases to tholeiite andesites. LREE enrichment, an Nb negative anomaly, the absence of a Ta trough and a high Nd isotope signature ( ɛNd t = + 6) are the most relevant geochemical features. The diabase bodies are up to 330 m in thickness and were sampled from bottom to top along several different sections, permitting the definition of an accumulation of clinopyroxene, olivine and plagioclase close to chilled margins at the bottom, and abundant pegmatoid layers at the top. Chemical profiles and mass-balance modelling suggest that the bulk rock and chilled margin compositions are not dissimilar, defining an unusual S-type vertical compositional profile for large (> 50 m thick) sills, which in turn strongly suggests a single magma pulse and a probable gravitational settling. Assuming chilled margin samples as the parental magma, as well as Cr-enriched samples as cumulate layers, a two-stage liquid line of descent has been established, the first one consisting of a clinopyroxene-plagioclase-olivine cumulate assemblage. A second stage in relation to the depletion in Ti, Fe and V is accounted for by ilmenite fractionation, along with that of clinopyroxene, plagioclase and olivine fractionation. Thermobarometric estimations reveal that the clinopyroxene (around 1100 °C and 197 MPa) was a late mineral phase, whereas the plagioclase (around 1200 °C) was pre- to syn-emplacement, in agreement with the presence only of plagioclase phenocrysts in the chilled margins and the very abundant positive Eu anomaly. The energy constraint modelling is consistent with the lack of a significant assimilation process owing to the high temperature contrast between the country rock and the magma itself. The compositional characteristics of chilled margins enable them to be ruled out as primary melts in equilibrium with mantle olivine (Fo 91), a certain amount of olivine fractionation being required, which might have occurred in magma conduits en route to shallow emplacement levels in the crust. Spinel lherzolitic xenoliths from the European Cenozoic alkaline magmatism appear to be unsuitable protoliths to account for the chilled margin compositions. Instead, a hybrid mantle source consisting of a small amount of OIB-mantle component (5 wt.%) and a depleted end-member mantle component seems to be a plausible protolith, resulting in a good fit with the fractionation-corrected chilled margin trends for 10% of partial melting.

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.

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).

Investigating Dueling Scenarios in NGC 7582 with Broadband X-ray Spectroscopy

NASA Astrophysics Data System (ADS)

Rivers, E.

2015-09-01

NGC 7582 is a well-studied X-ray bright Seyfert 2 with moderately heavy (NH = 10^{23} - 10^{24} cm^{-2}), highly variable absorption and unusually strong reflection spectral features. The spectral shape changed around the year 2000, dropping in observed flux and becoming much more highly absorbed. Two scenarios have been put forth to explain this spectral change: 1) the source "shut off" around this time, decreasing in intrinsic luminosity, with a delayed decrease in reflection features due to the light crossing time of the Compton-thick material or 2) the source is a "hidden nucleus" which has recently become more heavily obscured, with only a portion of the power law continuum leaking through. NuSTAR observed NGC 7582 twice in 2012 two weeks apart in order to quantify the reflection using high-quality data above 10 keV. We analyze both NuSTAR observations placing them in the context of historical X-ray, infrared and optical observations, including re-analysis of RXTE data from 2003-2005. We find that the most plausible scenario is that NGC 7582 has a hidden nucleus which has recently become more heavily absorbed by a patchy torus with a covering fraction of 80-90% and a column density of 3.6 x 10^{24} cm^{-2}. We find the need for an additional highly variable full-covering absorber with NH= 4-6 x 10^{23} cm^{-2}, possibly associated with a hidden broad line region or a dust lane in the host galaxy.

Laboratory Simulations of Planetary Surfaces: Understanding Regolith Physical Properties from Remote Photopolarimetric Observations

NASA Astrophysics Data System (ADS)

Nelson, Robert M.; Boryta, Mark; Hapke, Bruce W.; Manatt, Kenneth S.; Shkuratov, Yuriy; Psarev, Vladimir; Vandervoort, Kurt; Kroner, Desire; Nebedum, Adaze; Vides, Christina; Quinones, John

2017-10-01

We present reflectance and polarization phase curve measurements for a suite of highly reflective planetary regolith analogues with physical characteristics that might be expected on the surface of an atmosphereless solar system body (ASSB). We studied thirteen well-sorted particle size fractions of aluminum oxide (Al2O3) in the laboratory with a goniometric photopolarimeter (GPP) of novel design.These results are highly relevant to understanding the unusual negative polarization behavior observed near small phase angles that has been reported over several decades on highly reflective ASSBs such as the asteroids 44 Nysa, 64 Angelina (Harris et al., 1989) and the Galilean satellites Io, Europa and Ganymede (Rosenbush et al., 1997; Mishchenko et al., 2006). Our measurements are consistent with the hypothesis that the surfaces of these ASSBs effectively scatter electromagnetic radiation as if they were extremely fine grained with void space >~95%, and grain sizes of the order <= λ. This portends consequences for efforts to deploy surface landers on high ASSB’s such as Europa. These results also have relevance to the field of terrestrial geo-engineering particularly to proposals for modifying Earth’s radiation balance by injecting Al2O3 particulates into the stratosphere for the purpose of offsetting the effect of anthropogenic greenhouse gas emissions (Teller et al., 1997).Harris et al., 1989 . Icarus 81, 365-374.Mishchenko et al., 2006 Applied Optics, 45, 4459-4463.Rosenbush et al, 1997, Astrophys. J. 487, 402-414.Teller et al., 1997. UCRL-JC-128715.

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.

Reconfiguration of a flexible fiber immersed in a 2D dense granular flow close to the jamming transition

NASA Astrophysics Data System (ADS)

Kolb, Evelyne; Algarra, Nicolas; Vandembroucq, Damien; Lazarus, Arnaud

2015-11-01

We propose a new fluid/structure interaction in the unusual case of a dense granular medium flowing against an elastic fibre acting as a flexible intruder. We experimentally studied the deflection of a mylar flexible beam clamped at one side, the other free side facing a 2D granular flow in a horizontal cell moving at a constant velocity. We investigated the reconfiguration of the fibre as a function of the fibre's rigidity and of the granular packing fraction close but below the jamming in 2D. Imposing the fibre geometry like its length or thickness sets the critical buckling force the fibre is able to resist if it was not supported by lateral grains, while increasing the granular packing fraction might laterally consolidate the fibre and prevent it from buckling. But on the other side, the approach to jamming transition by increasing the granular packing fraction will be characterized by a dramatically increasing size of the cluster of connected grains forming a solid block acting against the fibre, which might promote the fibre's deflection. Thus, we investigated the granular flow fields, the fibre's deflexion as well as the forces experienced by the fibre and compared them with theoretical predictions from elastica for different loadings along the fibre. PMMH, CNRS UMR 7636, UPMC, ESPCI-ParisTech, 10 rue Vauquelin, 75231 Paris Cedex 05, France.

Purification and properties of an alkaline ribonuclease from the hepatic cytosol fraction of bullfrog, Rana catesbeiana.

PubMed

Nagano, H; Kiuchi, H; Abe, Y; Shukuya, R

1976-07-01

In the hepatic cytosol fraction of bullfrog, Rana catesbeiana, an alkaline RNase [EC 3.1.4.22] exists in two forms. One is the free form of RNase, which elutes from a carboxymethyl-cellulose column at a concentration of 0.2 M NaC1. The other is a masked or latent form (RNase-RNase inhibitor complex) which is not adsorbed on the carboxymethyl-cellulose column and which can be converted to the free form of RNase by the addition of p-chloromercuribenzoate. Electrophoretically pure RNase was obtained by the following procedure. The unadsorbed fraction of hepatic cytosol on a column of carboxymethyl-cellulose was treated with p-chloromercuribenzoate and then applied to a second carboxymethyl-cellulose column. The molar weight of RNase was determined to be approximately 12,000 by gel filtration and polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. From the results of gel filtration, the molecular weight of the RNase-RNase inhibitor complex was 130,000. The RNase hydrolyzed poly C, poly U, and poly I, but not poly A or poly G. When poly C was used as a substrate, 2',3'-cyclic CMP as an intermediate and 3'-CMP as a final product were identified. The results of amino acid analysis indicated the presence of an unusual component. The general properties of the RNase and the RNase-RNase inhibitor complex are also reported.

A Model of the Temporal Variability of Optical Light from Extrasolar Terrestrial Planets

NASA Astrophysics Data System (ADS)

Ford, E. B.; Seager, S.; Turner, E. L.

2001-05-01

New observatories such as TPF (NASA) and Darwin (ESA) are being designed to detect light directly from terrestrial-mass planets. Such observations will provide new data to constrain theories of planet formation and may identify the possible presence of liquid water and even spectroscopic signatures suggestive of life. We model the light scattered by Earth-like planets focusing on temporal variability due to planetary rotation and weather. Since a majority of the scattered light comes from only a small fraction of the planet's surface, significant variations in brightness are possible. The variations can be as large as a factor of two for a cloud-free planet which has a range of albedos similar to those of the different surfaces found on Earth. If a significant fraction of the observed light is scattered by the planet's atmosphere, including clouds, then the amplitude of variations due to surface features will be diluted. Atmospheric variability (e.g. clouds) itself is extremely interesting because it provides evidence for weather. The planet's rotation period, fractional ice and cloud cover, gross distribution of land and water on the surface, large scale weather patterns, large regions of unusual reflectivity or color (such as major desserts or vegetation's "red edge") as well as the geometry of its spin, orbit, and illumination relative to the observer all have substantial effects on the planet's rotational light curve.

[Antimicrobial effect on some zoonotic bacteria, of the cell-free fermentation fluid and purified peptide fraction of the entomopathogenic bacterium, Xenorhabdus budapestensis].

PubMed

Burgettiné Böszörményi, Erzsébet; Barcs, István; Domján, Gyula; Bélafiné Bakó, Katalin; Fodor, András; Makrai, László; Vozik, Dávid

2015-11-01

Many multi-resistant patogens appear continuously resulting in a permanent need for the development of novel antibiotics. A large number of antibiotics introduced in clinical and veterinary practices are not effective. Antibacterial peptides with unusual mode of action may represent a promising option against multi-resistant pathogens. The entomopathogenic Xenorhabdus budapestensis bacteria produce several different antimicrobial peptides compounds such as bicornutin-A and fabclavin. The aim of the authors was to evaluate the in vitro antibacterial effect of Xenorhabdus budapestensis using zoonotic patogen bacteria. Cell-free conditioned media and purified peptide fractions of Xenorhabdus budapestensis were tested on Gram-positive (Rhodococcus equi, Erysipelothrix rhusiopathia, Staphylococcus aureus, Streptococcus equi, Corynebacterium pseudotuberculosis, Listeria monocytagenes) and Gram-negative bacteria (Salmonella gallinarum, Salmonella derbi, Bordatella bronchoseptica, Escherichia coli, Pasteurella multocida, Aeromonas hydrophila) using agar diffusion test on blood agar plates. It was found that Xenorhabdus budapestensis bacteria produced compounds with strong and dose-dependent effects on the tested organisms. Purified peptid fraction exerted a more marked effect than cell free conditioned media. Gram-positive bacteria were more sensitive to this antibacterial effect than Gram-negative bacteria. Antibacterial peptide compound from Xenorhabdus budapestensis exert marked antibacterial effect on zoonotic patogen bacteria and they should be further evaluated in future for their potential use in the control or prevention of zoonoses.

Confined crystallization, crystalline phase deformation and their effects on the properties of crystalline polymers

NASA Astrophysics Data System (ADS)

Wang, Haopeng

With the recent advances in processing and catalyst technology, novel morphologies have been created in crystalline polymers and they are expected to substantially impact the properties. To reveal the structure-property relationships of some of these novel polymeric systems becomes the primary focus of this work. In the first part, using an innovative layer-multiplying coextrusion process to obtain assemblies with thousands of polymer nanolayers, dominating "in-plane" lamellar crystals were created when the confined poly(ethylene oxide) (PEO) layers were made progressively thinner. When the thickness was confined to 25 nanometers, the PEO crystallized as single, high-aspect-ratio lamellae that resembled single crystals. This crystallization habit imparted more than two orders of magnitude reduction in the gas permeability. The dramatic decrease in gas permeability was attributed to the reduced diffusion coefficient, because of the increase in gas diffusion path length through the in-plane lamellae. The temperature dependence of lamellar orientation and the crystallization kinetics in the confined nanolayers were also investigated. The novel olefinic block copolymer (OBC) studied in the second part consisted of long crystallizable sequences with low comonomer content alternating with rubbery amorphous blocks with high comonomer content. The crystallizable blocks formed lamellae that organized into space-filling spherulites even when the fraction of crystallizable block was so low that the crystallinity was only 7%. These unusual spherulites were highly elastic and recovered from strains as high as 300%. These "elastic spherulites" imparted higher strain recovery and temperature resistance than the conventional random copolymers that depend on isolated, fringed micellar-like crystals to provide the junctions for the elastomeric network. In the third part, positron annihilation lifetime spectroscopy (PALS) was used to obtain the temperature dependence of the free volume hole size in propylene/ethylene copolymers over a range in comonomer content. Above the glass transition temperature (Tg), the reduced free volume hole size and the densification of the amorphous phase were attributed to constraint imposed on rubbery amorphous chain segments by attached chain segments in crystals. However constant free volume fraction was found at Tg, across the crystallinity range of the copolymers, in agreement with the iso-free volume concept of glass transition.

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

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.

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' ...

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...

Adult amphibian epidermal proteins: biochemical characterization and developmental appearance.

PubMed

Reeves, O R

1975-08-01

The keratin-like proteins (KLPs) from the epidermis of adult frogs of the species Xenopus laevis have been isolated and biochemically characterized by means of polyacrylamide gel electrophoresis, amino acid analysis, tryptic peptide mapping, amino-terminal end-group analysis and isoelectric focusing. One particular protein fraction of rather unusual amino acid composition found only in epidermal tissue was isolated in quantity by preparative gel electrophoresis and monospecific antibodies prepared against it. Using this anti-KLP antibody preparation it was possible to show that at least one kine of keratin-like protein characteristic of the adult epidermis first appears within the larval epidermis during metamorphosis. This is the first reported biochemical characterization of a tissue-specific protien from adult amphibian skin.

Binary rare earth element-Ni/Co metallic glasses with distinct β-relaxation behaviors

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

Zhu, Z. G.; Wang, Z.; Wang, W. H., E-mail: whw@iphy.ac.cn

2015-10-21

We report the formation of a series of rare earth element (RE)-Ni/Co binary metallic glasses (MGs) with unusual distinct β-relaxation peak compared with that of most of the reported MGs which usually exhibit as an excess wing or a shoulder. The β-relaxation behavior of RE-Ni/Co MGs is sensitive to the composition and the atomic radii of the RE and can be tuned through changing the fraction of RE-Ni (or Co) atomic pairs. The novel RE-Ni/Co MGs with distinct β-relaxation can serve as model system to investigate the nature of the β-relaxation as well as its relations with other physical andmore » mechanical properties of MGs.« less

Refractory inclusions with unusual chemical compositions from the Vigarano carbonaceous chondrite

NASA Technical Reports Server (NTRS)

Sylvester, Paul J.; Grossman, Lawrence; Macpherson, Glenn J.

1992-01-01

Neutron activation was used to test ten inclusions, nine Vigarano and one from Leoville, for major and trace elements. Six Vigarano refractory inclusions have refractory element fractionations that are rare or absent in Allende inclusions. Vig 1623-11 has Th/La and Ir/Mo ratios that are lower than those of any Allende Group I or modified Group I inclusions, and Os/La, Ir/La, and Zr/Hf ratios that are among the lowest in those inclusions. The low Os/La, Ir/La, and Ir/Mo ratios seem to require nonrepresentative sampling of condensate phase in the nebula to a degree that is usual for Allende Group I and modified group I inclusions. The nature and origins of the different inclusions are discussed.

Perineural tumour spread from colon cancer, an unusual cause of trigeminal neuropathy - a case report

PubMed Central

Nair, Kavitha; George, Thomas; El Beltagi, Ahmed

2015-01-01

Malignant trigeminal neuralgia due to perineural spread along the branches of the trigeminal nerve, is known to commonly occur secondary to squamous cell carcinomas, lymphomas and adenoid cystic carcinomas in the head and neck region. Rarely metastases to the trigeminal nerve have been reported in breast cancer, prostate cancer and colon cancer. To the best of our knowledge trigeminal neuropathy due to skull base metastases and perineural spread along the maxillary (V2) and mandibular (V3) branches of the trigeminal nerve, secondary to colon cancer, has not been previously reported. The diagnosis in our index case was made on magnetic resonance imaging, and patient was treated accordingly by fractionated stereotactic radiotherapy, with subsequent relief of her pain. PMID:26629299

Phaeochromocytoma: state-of-the-art.

PubMed

Donckier, J E; Michel, L

2010-01-01

Phaeochromocytomas are catecholamine-secreting tumours that arise from chromaffin cells of the adrenal medulla and extra-adrenal sites. Extra-adrenal phaeochromocytomas are called paragangliomas. A diagnosis of phaeochromocytoma is suspected by typical paroxysmal symptoms, unusual or refractory hypertension, discovery of an adrenal incidentaloma or a family history of phaeochromocytoma or paraganglioma, possibly associated with other genetic syndromes (multiple endocrine neoplasia type 2 A or B, neurofibromatosis type 1 and von Hippel-Lindau disease). It can be confirmed by measurements of urinary or plasma fractionated catecholamines and metanephrines. The best diagnostic performances are achieved by metanephrines. Twenty-four hour urine fractionated metanephrines are still recommended as a screening test but some experts prefer plasma measurements in high-risk patients. Increased serum chromogranin-A levels, combined with high catecholamine or metanephrine in a patient with normal renal function is also a tool, virtually diagnostic of phaeochromocytoma. Recent studies have suggested that 25% of patients with phaeochromocytoma have germline mutations of several genes (NF1, VHL, SDHD, SDHB and RET). Thus, genetic testing should be carried out according to an algorithm of risk factors and specific characteristics. Once a biochemical diagnosis of phaeochromocytoma is made, a CT scan or MRI of the abdomen and pelvis should be performed first. If these investigations remain negative, the chest and neck should be explored. After anatomical imaging, functional imaging by 123I-MIBG should be considered. If the MIBG scan is negative, other imaging modalities have recently proven to be useful (PET, Octreoscan). After localization, the treatment of phaeochromocytoma is a surgical resection, which may be laparoscopic. Preoperative preparation with alpha- and beta-adrenergic blockade and/or calcium channel blockers associated with volume expansion is essential. Malignant phaeochromocytoma is rare and its treatment still unsatisfying. Phaeochromocytoma during pregnancy is also rare and its diagnosis easily missed because of its clinical resemblance to pre-eclampsia.

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.

Intra-isolate genome variation in arbuscular mycorrhizal fungi persists in the transcriptome.

PubMed

Boon, E; Zimmerman, E; Lang, B F; Hijri, M

2010-07-01

Arbuscular mycorrhizal fungi (AMF) are heterokaryotes with an unusual genetic makeup. Substantial genetic variation occurs among nuclei within a single mycelium or isolate. AMF reproduce through spores that contain varying fractions of this heterogeneous population of nuclei. It is not clear whether this genetic variation on the genome level actually contributes to the AMF phenotype. To investigate the extent to which polymorphisms in nuclear genes are transcribed, we analysed the intra-isolate genomic and cDNA sequence variation of two genes, the large subunit ribosomal RNA (LSU rDNA) of Glomus sp. DAOM-197198 (previously known as G. intraradices) and the POL1-like sequence (PLS) of Glomus etunicatum. For both genes, we find high sequence variation at the genome and transcriptome level. Reconstruction of LSU rDNA secondary structure shows that all variants are functional. Patterns of PLS sequence polymorphism indicate that there is one functional gene copy, PLS2, which is preferentially transcribed, and one gene copy, PLS1, which is a pseudogene. This is the first study that investigates AMF intra-isolate variation at the transcriptome level. In conclusion, it is possible that, in AMF, multiple nuclear genomes contribute to a single phenotype.

Chemical camouflage--a frog's strategy to co-exist with aggressive ants.

PubMed

Rödel, Mark-Oliver; Brede, Christian; Hirschfeld, Mareike; Schmitt, Thomas; Favreau, Philippe; Stöcklin, Reto; Wunder, Cora; Mebs, Dietrich

2013-01-01

Whereas interspecific associations receive considerable attention in evolutionary, behavioural and ecological literature, the proximate bases for these associations are usually unknown. This in particular applies to associations between vertebrates with invertebrates. The West-African savanna frog Phrynomantis microps lives in the underground nest of ponerine ants (Paltothyreus tarsatus). The ants usually react highly aggressively when disturbed by fiercely stinging, but the frog is not attacked and lives unharmed among the ants. Herein we examined the proximate mechanisms for this unusual association. Experiments with termites and mealworms covered with the skin secretion of the frog revealed that specific chemical compounds seem to prevent the ants from stinging. By HPLC-fractionation of an aqueous solution of the frogs' skin secretion, two peptides of 1,029 and 1,143 Da were isolated and found to inhibit the aggressive behaviour of the ants. By de novo sequencing using tandem mass spectrometry, the amino acid sequence of both peptides consisting of a chain of 9 and 11 residues, respectively, was elucidated. Both peptides were synthesized and tested, and exhibited the same inhibitory properties as the original frog secretions. These novel peptides most likely act as an appeasement allomone and may serve as models for taming insect aggression.

Cosmic reionization on computers. II. Reionization history and its back-reaction on early galaxies

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

Gnedin, Nickolay Y.; Kaurov, Alexander A., E-mail: gnedin@fnal.gov, E-mail: kaurov@uchicago.edu

We compare the results from several sets of cosmological simulations of cosmic reionization, produced under the Cosmic Reionization On Computers project, with existing observational data on the high-redshift Lyα forest and the abundance of Lyα emitters. We find good consistency with the observational measurements and previous simulation work. By virtue of having several independent realizations for each set of numerical parameters, we are able to explore the effect of cosmic variance on observable quantities. One unexpected conclusion we are forced into is that cosmic variance is unusually large at z > 6, with both our simulations and, most likely, observationalmore » measurements still not fully converged for even such basic quantities as the average Gunn-Peterson optical depth or the volume-weighted neutral fraction. We also find that reionization has little effect on the early galaxies or on global cosmic star formation history, because galaxies whose gas content is affected by photoionization contain no molecular (i.e., star-forming) gas in the first place. In particular, measurements of the faint end of the galaxy luminosity function by the James Webb Space Telescope are unlikely to provide a useful constraint on reionization.« less

Next-generation sequencing detects repetitive elements expansion in giant genomes of annual killifish genus Austrolebias (Cyprinodontiformes, Rivulidae).

PubMed

García, G; Ríos, N; Gutiérrez, V

2015-06-01

Among Neotropical fish fauna, the South American killifish genus Austrolebias (Cyprinodontiformes: Rivulidae) constitutes an excellent model to study the genomic evolutionary processes underlying speciation events. Recently, unusually large genome size has been described in 16 species of this genus, with an average DNA content of about 5.95 ± 0.45 pg per diploid cell (mean C-value of about 2.98 pg). In the present paper we explore the possible origin of this unparallel genomic increase by means of comparative analysis of the repetitive components using NGS (454-Roche) technology in the lowest and highest Rivulidae genomes. Here, we provide the first annotated Rivulidae-repeated sequences composition and their relative repetitive fraction in both genomes. Remarkably, the genomic proportion of the moderately repetitive DNA in Austrolebias charrua genome represents approximately twice (45%) of the repetitive components of the highly related rivulinae taxon Cynopoecilus melanotaenia (25%). Present work provides evidence about the impact of the repeat families that could be distinctly proliferated among sublineages within Rivulidae fish group, explaining the great genome size differences encompassing the differentiation and speciation events in this family.

Synthesis, fractionation, and thin film processing of nanoparticles using the tunable solvent properties of carbon dioxide gas expanded liquids

NASA Astrophysics Data System (ADS)

Anand, Madhu

Nanoparticles have received significant attention because of their unusual characteristics including high surface area to volume ratios. Materials built from nanoparticles possess unique chemical, physical, mechanical and optical properties. Due to these properties, they hold potential in application areas such as catalysts, sensors, semiconductors and optics. At the same time, CO 2 in the form of supercritical fluid or CO2 gas-expanded liquid mixtures has gained significant attention in the area of processing nanostructures. This dissertation focuses on the synthesis and processing of nanoparticles using CO2 tunable solvent systems. Nanoparticle properties depend heavily on their size and, as such, the ability to finely control the size and uniformity of nanoparticles is of utmost importance. Solution based nanoparticle formation techniques are attractive due to their simplicity, but they often result in the synthesis of particles with a wide size range. To address this limitation, a post-synthesis technique has been developed in this dissertation to fractionate polydisperse nanoparticles ( s . = 30%) into monodisperse fractions ( s . = 8%) using tunable physicochemical properties of CO 2 expanded liquids, where CO2 is employed as an antisolvent. This work demonstrates that by controlling the addition of CO2 (pressurization) to an organic dispersion of nanoparticles, the ligand stabilized nanoparticles can be size selectively precipitated within a novel high pressure apparatus that confines the particle precipitation to a specified location on a surface. Unlike current techniques, this CO2 expanded liquid approach provides faster and more efficient particle size separation, reduction in organic solvent usage, and pressure tunable size selection in a single process. To improve our fundamental understanding and to further refine the size separation process, a detailed study has been performed to identify the key parameters enabling size separation of various nanoparticle populations. This study details the influence of various factors on the size separation process, such as the types of nanoparticles, ligand type and solvent type as well as the use of recursive fractionation and the time allowed for settling during each fractionation step. This size selective precipitation technique was also applied to fractionate and separate polydisperse dispersions of CdSe/ZnS semiconductor nanocrystals into very distinct size and color fractions based solely on the pressure tunable solvent properties of CO2 expanded liquids. This size selective precipitation of nanoparticles is achieved by finely tuning the solvent strength of the CO2/organic solvent medium by simply adjusting the applied CO2 pressure. These subtle changes affect the balance between osmotic repulsive and van der Waals attractive forces thereby allowing fractionation of the nanocrystals into multiple narrow size populations. Thermodynamic analysis of nanoparticle size selective fractionation was performed to develop a theoretical model based on the thermodynamic properties of gas expanded liquids. We have used the general phenomenon of nanoparticle precipitation with CO2 expanded liquids to create dodecanethiol stabilized gold nanoparticle thin films. This method utilizes CO2 as an anti-solvent for low defect, wide area gold nanoparticle film formation employing monodisperse gold nanoparticles. Dodecanethiol stabilized gold particles are precipitated from hexane by controllably expanding the solution with carbon dioxide. Subsequent addition of carbon dioxide as a dense supercritical fluid then provides for removal of the organic solvent while avoiding the dewetting effects common to evaporating solvents. Unfortunately, the use of carbon dioxide as a neat solvent in nanoparticles synthesis and processing is limited by the very poor solvent strength of dense phase CO2. As a result, most current techniques employed to synthesize and disperse nanoparticles in neat carbon dioxide require the use of environmentally persistent fluorinated compounds as metal precursors and/or stabilizing ligands. This dissertation presents the first report of the simultaneous synthesis and stabilization of metallic nanoparticles in carbon dioxide solvent without the use of any fluorinated compounds thereby further enabling the use of CO 2 as a green solvent medium in nanomaterials synthesis and processing.

Phytotoxic Effects and Phytochemical Fingerprinting of Hydrodistilled Oil, Enriched Fractions, and Isolated Compounds Obtained from Cryptocarya massoy (Oken) Kosterm. Bark.

PubMed

Rolli, Enrico; Marieschi, Matteo; Maietti, Silvia; Guerrini, Alessandra; Grandini, Alessandro; Sacchetti, Gianni; Bruni, Renato

2016-01-01

The hydrodistilled oil of Cryptocarya massoy bark was characterized by GC-FID and GC/MS analyses, allowing the identification of unusual C10 massoia lactone (3, 56.2%), C12 massoia lactone (4, 16.5%), benzyl benzoate (1, 12.7%), C8 massoia lactone (3.4%), δ-decalactone (5, 1.5%), and benzyl salicylate (2, 1.8%) as main constituents. The phytotoxic activities of the oil, three enriched fractions (lactone-rich, ester-rich, and sesquiterpene-rich), and four constituents (compounds 1, 2, 5, and δ-dodecalactone (6)) against Lycopersicon esculentum and Cucumis sativus seeds and seedlings were screened. At a concentration of 1000 μl/l, the essential oil and the massoia lactone-rich fraction caused a complete inhibition of the germination of both seeds, and, when applied on tomato plantlets, they induced an 85 and 100% dieback, respectively. These performances exceeded those of the well-known phytotoxic essential oils of Syzygium aromaticum and Cymbopogon citratus, already used in commercial products for the weed and pest management. The same substances were also evaluated against four phytopathogenic bacteria and ten phytopathogenic fungi, providing EC50 values against the most susceptible strains in the 100-500 μl/l range for the essential oil and in the 10-50 μl/l range for compound 6 and the lactone-rich fraction. The phytotoxic behavior was related mainly to massoia lactones and benzyl esters, while a greater amount of 6 may infer a good activity against some phytopathogenic fungi. Further investigations of these secondary metabolites are warranted, to evaluate their use as natural herbicides. Copyright © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

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.

Theoretical estimation of equilibrium sulfur isotope fractionations among aqueous sulfite species: Implications for isotope models of microbial sulfate reduction

NASA Astrophysics Data System (ADS)

Eldridge, D. L.; Farquhar, J.; Guo, W.

2015-12-01

Sulfite (sensu lato), an intermediate in a variety sulfur redox processes, plays a particularly important role in microbial sulfate reduction. It exists intracellularly as multiple species between sets of enzymatic reactions that transform sulfate to sulfide, with the exact speciation depending on pH, T, and ionic strength. However, the complex speciation of sulfite is ignored in current isotope partitioning models of microbial sulfate reduction and simplified solely to the pyramidal SO32- (sulfite sensu stricto), due to a lack of appropriate constraints. We theoretically estimated the equilibrium sulfur isotope fractionations (33S/32S, 34S/32S, 36S/32S) among all documented sulfite species in aqueous solution, including sulfite (SO32-), bisulfite isomers and dimers ((HS)O3-, (HO)SO2-, S2O52-), and SO2(aq), through first principles quantum mechanical calculations. The calculations were performed at B3LYP/6-31+G(d,p) level using cluster models with 30-40 water molecules surrounding the solute. Our calculated equilibrium fractionation factors compare well to the available experimental constraints and suggest that the minor and often-ignored tetrahedral (HS)O3- isomer of bisulfite strongly influences isotope partitioning behavior in the sulfite system under most environmentally relevant conditions, particularly fractionation magnitudes and unusual temperature dependence. For example, we predict that sulfur isotope fractionation between sulfite and bulk bisulfite in solution should have an apparent inverse temperature dependence due to the influence of (HS)O3- and its increased stability at higher temperatures. Our findings highlight the need to appropriately account for speciation/isomerization of sulfur species in sulfur isotope studies. We will also present similar calculation results of other aqueous sulfur compounds (e.g., H2S/HS-, SO42-, S2O32-, S3O62-, and poorly documented SO22- species), and discuss the implication of our results for microbial sulfate reduction models and other sulfur-redox processes in nature.

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.

Stable-isotope geochemistry of the Pierina high-sulfidation Au-Ag deposit, Peru: Influence of hydrodynamics on SO42--H2S sulfur isotopic exchange in magmatic-steam and steam-heated environments

USGS Publications Warehouse

Fifarek, R.H.; Rye, R.O.

2005-01-01

The Pierina high-sulfidation Au-Ag deposit formed 14.5 my ago in rhyolite ash flow tuffs that overlie porphyritic andesite and dacite lavas and are adjacent to a crosscutting and interfingering dacite flow dome complex. The distribution of alteration zones indicates that fluid flow in the lavas was largely confined to structures but was dispersed laterally in the tuffs because of a high primary and alteration-induced permeability. The lithologically controlled hydrodynamics created unusual fluid, temperature, and pH conditions that led to complete SO42--H2S isotopic equilibration during the formation of some magmatic-steam and steam-heated alunite, a phenomenon not previously recognized in similar deposits. Isotopic data for early magmatic hydrothermal and main-stage alunite (??34S=8.5??? to 31.7???; ??18 OSO4=4.9??? to 16.5???; ??18 OOH=2.2??? to 14.4???; ??D=-97??? to -39???), sulfides (??34 S=-3.0??? to 4.3???), sulfur (??34S=-1.0??? to 1.1???), and clay minerals (??18O=4.3??? to 12.5???; ??D=-126??? to -81???) are typical of high-sulfidation epithermal deposits. The data imply the following genetic elements for Pierina alteration-mineralization: (1) fluid and vapor exsolution from an I-type magma, (2) wallrock buffering and cooling of slowing rising vapors to generate a reduced (H2S/SO4???6) highly acidic condensate that mixed with meteoric water but retained a magmatic ??34S???S signature of ???1???, (3) SO2 disproportionation to HSO4- and H2S between 320 and 180 ??C, and (4) progressive neutralization of laterally migrating acid fluids to form a vuggy quartz???alunite-quartz??clay???intermediate argillic???propylitic alteration zoning. Magmatic-steam alunite has higher ??34S (8.5??? to 23.2???) and generally lower ??18OSO4 (1.0 to 11.5???), ??18OOH (-3.4 to 5.9???), and ??D (-93 to -77???) values than predicted on the basis of data from similar occurrences. These data and supporting fluid-inclusion gas chemistry imply that the rate of vapor ascent for this environment was unusually slow, which provided sufficient time for the uptake of groundwater and partial to complete SO42--H2S isotopic exchange. The slow steam velocities were likely related to the dispersal of the steam column as it entered the tuffs and possibly to intermediate exsolution rates from magmatic brine. The low ??D values may also partly reflect continuous degassing of the mineralizing magma. Similarly, data for steam-heated alunite (??34S=12.3??? to 27.2???; ??18OSO4=11.7??? to 13.0???; ??18OOH=6.6??? to 9.4???; ??D=-59??? to -42???) are unusual and indicate a strong magmatic influence, relatively high temperatures (140 to 180 ??C, based on ??18 OSO4-OH fractionations), and partial to complete sulfur isotopic exchange between steam-heated sulfate and H2S. Restricted lithologically controlled fluid flow in the host tuffs allowed magmatic condensate to supplant meteoric groundwater at the water table and create the high-temperature low-pH conditions that permitted unusually rapid SO42--H2S isotopic equilibration (50-300 days) and (or) long sulfate residence times for this environment. Late void-filling barite (??34S=7.4??? to 29.7???; ??18OSO4=-0.4??? to 15.1???) and later void-filling goethite (??18O=-11.8??? to 0.2???) document a transition from magmatic condensate to dominantly meteoric water in steam-heated fluids during cooling and collapse of the hydrothermal system. These steam-heated fluids oxidized the top ???300 m of the deposit by leaching sulfides, redistributing metals, and precipitating barite??acanthite??gold and goethite-hematite ??gold. Steam-heated oxidation, rather than weathering, was critical to forming the orebody in that it not only released encapsulated gold but likely enriched the deposit to ore-grade Au concentrations. ?? 2004 Elsevier B.V. All rights reserved.

Identification of genotoxic compounds in crude oil using fractionation according to distillation, polarity and Kow.

PubMed

Park, Shin Yeong; Lee, Hyo Jin; Khim, Jong Seong; Kim, Gi Beum

2017-01-30

We examined the degree of DNA damage caused by fractions of crude oil in accordance with the boiling points, polarity and log K ow . Relatively high DNA damage was observed in the aromatic fraction (290-330°C) and resin and polar fraction (350-400°C). The resin and polar fraction showed relatively high genotoxicity compared with the aliphatic and aromatic fraction at the 1-4 log K ow range. At the 6-7 log K ow range, the aromatic fraction showed relatively high DNA damage compared with the aliphatic and resin and polar fraction. In particular, every detailed fraction in accordance with the log K ow values (aliphatic and aromatic (310-320°C) and resins and polar fractions (370-380°C)) showed one or less than one DNA damage. However, the fractions before separation in accordance with log K ow values (aliphatic and aromatic (310-320°C) and resin and polar (370-380°C) fractions) showed high DNA damage. Thus, we confirm the synergistic action between the detailed compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

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)

An improved genome assembly uncovers prolific tandem repeats in Atlantic cod.

PubMed

Tørresen, Ole K; Star, Bastiaan; Jentoft, Sissel; Reinar, William B; Grove, Harald; Miller, Jason R; Walenz, Brian P; Knight, James; Ekholm, Jenny M; Peluso, Paul; Edvardsen, Rolf B; Tooming-Klunderud, Ave; Skage, Morten; Lien, Sigbjørn; Jakobsen, Kjetill S; Nederbragt, Alexander J

2017-01-18

The first Atlantic cod (Gadus morhua) genome assembly published in 2011 was one of the early genome assemblies exclusively based on high-throughput 454 pyrosequencing. Since then, rapid advances in sequencing technologies have led to a multitude of assemblies generated for complex genomes, although many of these are of a fragmented nature with a significant fraction of bases in gaps. The development of long-read sequencing and improved software now enable the generation of more contiguous genome assemblies. By combining data from Illumina, 454 and the longer PacBio sequencing technologies, as well as integrating the results of multiple assembly programs, we have created a substantially improved version of the Atlantic cod genome assembly. The sequence contiguity of this assembly is increased fifty-fold and the proportion of gap-bases has been reduced fifteen-fold. Compared to other vertebrates, the assembly contains an unusual high density of tandem repeats (TRs). Indeed, retrospective analyses reveal that gaps in the first genome assembly were largely associated with these TRs. We show that 21% of the TRs across the assembly, 19% in the promoter regions and 12% in the coding sequences are heterozygous in the sequenced individual. The inclusion of PacBio reads combined with the use of multiple assembly programs drastically improved the Atlantic cod genome assembly by successfully resolving long TRs. The high frequency of heterozygous TRs within or in the vicinity of genes in the genome indicate a considerable standing genomic variation in Atlantic cod populations, which is likely of evolutionary importance.

Discordant K-Ar and Young Exposure Dates for the Windjana Sandstone, Kimberley, Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Vasconcelos, P. M.; Farley, K. A.; Malespin, C. A.; Mahaffy, P.; Ming, D.; McLennan, S. M.; Hurowitz, J. A.; Rice, Melissa S.

2016-01-01

K-Ar and noble gas surface exposure age measurements were carried out on the Windjana sandstone, Kimberley region, Gale Crater, Mars, by using the Sample Analysis at Mars instrument on the Curiosity rover. The sandstone is unusually rich in sanidine, as determined by CheMin X-ray diffraction, contributing to the high K2O concentration of 3.09 +/- 0.20 wt % measured by Alpha-Particle X-ray Spectrometer analysis. A sandstone aliquot heated to approximately 915 C yielded a K-Ar age of 627 +/- 50 Ma. Reheating this aliquot yielded no additional Ar. A second aliquot heated in the same way yielded a much higher K-Ar age of 1710 +/- 110 Ma. These data suggest incomplete Ar extraction from a rock with a K-Ar age older than 1710 Ma. Incomplete extraction at approximately 900 C is not surprising for a rock with a large fraction of K carried by Ar-retentive K-feldspar. Likely, variability in the exact temperature achieved by the sample from run to run, uncertainties in sample mass estimation, and possible mineral fractionation during transport and storage prior to analysis may contribute to these discrepant data. Cosmic ray exposure ages from He-3 and Ne-21 in the two aliquots are minimum values given the possibility of incomplete extraction. However, the general similarity between the He-3 (57 +/- 49 and 18 +/- 32 Ma, mean 30 Ma) and Ne-21 (2 +/- 32 and 83 +/- 24 Ma, mean 54 Ma) exposure ages provides no evidence for underextraction. The implied erosion rate at the Kimberley location is similar to that reported at the nearby Yellowknife Bay outcrop.

A Profile of an Endosymbiont-enriched Fraction of the Coral Stylophora pistillata Reveals Proteins Relevant to Microbial-Host Interactions*

PubMed Central

Weston, Andrew J.; Dunlap, Walter C.; Shick, J. Malcolm; Klueter, Anke; Iglic, Katrina; Vukelic, Ana; Starcevic, Antonio; Ward, Malcolm; Wells, Mark L.; Trick, Charles G.; Long, Paul F.

2012-01-01

This study examines the response of Symbiodinium sp. endosymbionts from the coral Stylophora pistillata to moderate levels of thermal “bleaching” stress, with and without trace metal limitation. Using quantitative high throughput proteomics, we identified 8098 MS/MS events relating to individual peptides from the endosymbiont-enriched fraction, including 109 peptides meeting stringent criteria for quantification, of which only 26 showed significant change in our experimental treatments; 12 of 26 increased expression in response to thermal stress with little difference affected by iron limitation. Surprisingly, there were no significant increases in antioxidant or heat stress proteins; those induced to higher expression were generally involved in protein biosynthesis. An outstanding exception was a massive 114-fold increase of a viral replication protein indicating that thermal stress may substantially increase viral load and thereby contribute to the etiology of coral bleaching and disease. In the absence of a sequenced genome for Symbiodinium or other photosymbiotic dinoflagellate, this proteome reveals a plethora of proteins potentially involved in microbial-host interactions. This includes photosystem proteins, DNA repair enzymes, antioxidant enzymes, metabolic redox enzymes, heat shock proteins, globin hemoproteins, proteins of nitrogen metabolism, and a wide range of viral proteins associated with these endosymbiont-enriched samples. Also present were 21 unusual peptide/protein toxins thought to originate from either microbial consorts or from contamination by coral nematocysts. Of particular interest are the proteins of apoptosis, vesicular transport, and endo/exocytosis, which are discussed in context of the cellular processes of coral bleaching. Notably, the protein complement provides evidence that, rather than being expelled by the host, stressed endosymbionts may mediate their own departure. PMID:22351649

The Role of Aldehyde Oxidase and Xanthine Oxidase in the Biotransformation of a Novel Negative Allosteric Modulator of Metabotropic Glutamate Receptor Subtype 5

PubMed Central

Morrison, Ryan D.; Blobaum, Anna L.; Byers, Frank W.; Santomango, Tammy S.; Bridges, Thomas M.; Stec, Donald; Brewer, Katrina A.; Sanchez-Ponce, Raymundo; Corlew, Melany M.; Rush, Roger; Felts, Andrew S.; Manka, Jason; Bates, Brittney S.; Venable, Daryl F.; Rodriguez, Alice L.; Jones, Carrie K.; Niswender, Colleen M.; Conn, P. Jeffrey; Lindsley, Craig W.; Emmitte, Kyle A.

2012-01-01

Negative allosteric modulation (NAM) of metabotropic glutamate receptor subtype 5 (mGlu5) represents a therapeutic strategy for the treatment of childhood developmental disorders, such as fragile X syndrome and autism. VU0409106 emerged as a lead compound within a biaryl ether series, displaying potent and selective inhibition of mGlu5. Despite its high clearance and short half-life, VU0409106 demonstrated efficacy in rodent models of anxiety after extravascular administration. However, lack of a consistent correlation in rat between in vitro hepatic clearance and in vivo plasma clearance for the biaryl ether series prompted an investigation into the biotransformation of VU0409106 using hepatic subcellular fractions. An in vitro appraisal in rat, monkey, and human liver S9 fractions indicated that the principal pathway was NADPH-independent oxidation to metabolite M1 (+16 Da). Both raloxifene (aldehyde oxidase inhibitor) and allopurinol (xanthine oxidase inhibitor) attenuated the formation of M1, thus implicating the contribution of both molybdenum hydroxylases in the biotransformation of VU0409106. The use of 18O-labeled water in the S9 experiments confirmed the hydroxylase mechanism proposed, because 18O was incorporated into M1 (+18 Da) as well as in a secondary metabolite (M2; +36 Da), the formation of which was exclusively xanthine oxidase-mediated. This unusual dual and sequential hydroxylase metabolism was confirmed in liver S9 and hepatocytes of multiple species and correlated with in vivo data because M1 and M2 were the principal metabolites detected in rats administered VU0409106. An in vitro-in vivo correlation of predicted hepatic and plasma clearance was subsequently established for VU0409106 in rats and nonhuman primates. PMID:22711749

Discovery of numerous novel small genes in the intergenic regions of the Escherichia coli O157:H7 Sakai genome

PubMed Central

Hücker, Sarah M.; Ardern, Zachary; Goldberg, Tatyana; Schafferhans, Andrea; Bernhofer, Michael; Vestergaard, Gisle; Nelson, Chase W.; Schloter, Michael; Rost, Burkhard; Scherer, Siegfried

2017-01-01

In the past, short protein-coding genes were often disregarded by genome annotation pipelines. Transcriptome sequencing (RNAseq) signals outside of annotated genes have usually been interpreted to indicate either ncRNA or pervasive transcription. Therefore, in addition to the transcriptome, the translatome (RIBOseq) of the enteric pathogen Escherichia coli O157:H7 strain Sakai was determined at two optimal growth conditions and a severe stress condition combining low temperature and high osmotic pressure. All intergenic open reading frames potentially encoding a protein of ≥ 30 amino acids were investigated with regard to coverage by transcription and translation signals and their translatability expressed by the ribosomal coverage value. This led to discovery of 465 unique, putative novel genes not yet annotated in this E. coli strain, which are evenly distributed over both DNA strands of the genome. For 255 of the novel genes, annotated homologs in other bacteria were found, and a machine-learning algorithm, trained on small protein-coding E. coli genes, predicted that 89% of these translated open reading frames represent bona fide genes. The remaining 210 putative novel genes without annotated homologs were compared to the 255 novel genes with homologs and to 250 short annotated genes of this E. coli strain. All three groups turned out to be similar with respect to their translatability distribution, fractions of differentially regulated genes, secondary structure composition, and the distribution of evolutionary constraint, suggesting that both novel groups represent legitimate genes. However, the machine-learning algorithm only recognized a small fraction of the 210 genes without annotated homologs. It is possible that these genes represent a novel group of genes, which have unusual features dissimilar to the genes of the machine-learning algorithm training set. PMID:28902868

Exchanging partially hydrogenated fat for palmitic acid in the diet increases LDL-cholesterol and endogenous cholesterol synthesis in normocholesterolemic women.

PubMed

Sundram, Kalyana; French, Margaret A; Clandinin, M Thomas

2003-08-01

Partial hydrogenation of oil results in fats containing unusual isomeric fatty acids characterized by cis and trans configurations. Hydrogenated fats containing trans fatty acids increase plasma total cholesterol (TC) and LDL-cholesterol while depressing HDL-cholesterol levels. Identifying the content of trans fatty acids by food labeling is overshadowed by a reluctance of health authorities to label saturates and trans fatty acids separately. Thus, it is pertinent to compare the effects of trans to saturated fatty acids using stable isotope methodology to establish if the mechanism of increase in TC and LDL-cholesterol is due to the increase in the rate of endogenous synthesis of cholesterol. Ten healthy normocholesterolemic female subjects consumed each of two diets containing approximately 30% of energy as fat for a fourweek period. One diet was high in palmitic acid (10.6% of energy) from palm olein and the other diet exchanged 5.6% of energy as partially hydrogenated fat for palmitic acid. This fat blend resulted in monounsaturated fatty acids decreasing by 4.9 % and polyunsaturated fats increasing by 2.7%. The hydrogenated fat diet treatment provided 3.1% of energy as elaidic acid. For each dietary treatment, the fractional synthesis rates for cholesterol were measured using deuterium-labeling procedures and blood samples were obtained for blood lipid and lipoprotein measurements. Subjects exhibited a higher total cholesterol and LDL-cholesterol level when consuming the diet containing trans fatty acids while also depressing the HDL-cholesterol level. Consuming the partially hydrogenated fat diet treatment increased the fractional synthesis rate of free cholesterol. Consumption of hydrogenated fats containing trans fatty acids in comparison to a mixtur e of palmitic and oleic acids increase plasma cholesterol levels apparently by increasing endogenous synthesis of cholesterol.

Spin morphologies and heat dissipation in spherical assemblies of magnetic nanoparticles

NASA Astrophysics Data System (ADS)

Anand, Manish; Carrey, Julian; Banerjee, Varsha

2016-09-01

Aggregates of magnetic nanoparticles (MNPs) exhibit unusual properties due to the interplay of small system size and long-range dipole-dipole interactions. Using the micromagnetic simulation software oommf, we study the spin morphologies and heat dissipation in micron-size spherical assemblies of MNPs. In particular, we examine the sensitivity of these properties to the dipolar strength, manipulated by the interparticle separation. As oommf is not designed for such a study, we have incorporated a novel scaling protocol for this purpose. We believe that it is essential for all studies where volume fractions are varied. Our main results are as follows: (i) Dense assemblies exhibit strong dipolar effects which yield local magnetic order in the core but not on the surface, where moments are randomly oriented. (ii) The probability distribution of ground-state energy exhibits a long high-energy tail for surface spins in contrast to small tails for the core spins. Consequently, there is a wide variation in the energy of surface spins but not the core spins. (iii) There is strong correlation between ground-state energy and heating properties on application of an oscillating magnetic field h (t ) =hocos2 π f t : the particles in the core heat uniformly, while those on the surface exhibit a wide range from cold to intensely hot. (iv) Specific choices of ho and f yield characteristic spatial heat distributions, e.g., hot surface and cold core, or vice versa. (iv) For all values of ho and f that we consider, heating was maximum at a specific volume fraction. These results are especially relevant in the context of contemporary applications such as hyperthermia and chemotherapy, and also for novel materials such as smart polymer beads and superspin glasses.

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.

Impact of photoluminescence temperature and growth parameter on the exciton localized in BxGa1-xAs/GaAs epilayers grown by MOCVD

NASA Astrophysics Data System (ADS)

Hidouri, Tarek; Saidi, Faouzi; Maaref, Hassen; Rodriguez, Philippe; Auvray, Laurent

2016-10-01

In this work, BxGa1-xAs/GaAs epilayers with three different boron compositions were elaborated by metal organic chemical vapor deposition (MOCVD) on GaAs (001) substrate. Structural study using High resolution X-ray diffraction (HRXRD) spectroscopy and Atomic Force Microscopy (AFM) have been used to estimate the boron fraction. The luminescence keys were carried out as functions of temperature in the range 10-300 K, by the techniques of photoluminescence (PL). The low PL temperature has shown an abnormal emission appeared at low energy side witch attributed to the recombination through the deep levels. In all samples, the PL peak energy and the full width at half maximum (FWHM), present an anomalous behavior as a result of the competition process between localized and delocalized carriers. We propose the Localized-state Ensemble model to explain the unusual photoluminescence behaviors. Electrical carriers generation, thermal escape, recapture, radiative and non-radiative lifetime are taken into account. The temperature-dependent photoluminescence measurements were found to be in reasonable agreement with the model of localized states. We controlled the evolution of such parameters versus composition by varying the V/III ratio to have a quantitative and qualitative understanding of the recombination mechanisms. At high temperature, the model can be approximated to the band-tail-state emission.

Architectural requirements for the Red Storm computing system.

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

Camp, William J.; Tomkins, James Lee

This report is based on the Statement of Work (SOW) describing the various requirements for delivering 3 new supercomputer system to Sandia National Laboratories (Sandia) as part of the Department of Energy's (DOE) Accelerated Strategic Computing Initiative (ASCI) program. This system is named Red Storm and will be a distributed memory, massively parallel processor (MPP) machine built primarily out of commodity parts. The requirements presented here distill extensive architectural and design experience accumulated over a decade and a half of research, development and production operation of similar machines at Sandia. Red Storm will have an unusually high bandwidth, low latencymore » interconnect, specially designed hardware and software reliability features, a light weight kernel compute node operating system and the ability to rapidly switch major sections of the machine between classified and unclassified computing environments. Particular attention has been paid to architectural balance in the design of Red Storm, and it is therefore expected to achieve an atypically high fraction of its peak speed of 41 TeraOPS on real scientific computing applications. In addition, Red Storm is designed to be upgradeable to many times this initial peak capability while still retaining appropriate balance in key design dimensions. Installation of the Red Storm computer system at Sandia's New Mexico site is planned for 2004, and it is expected that the system will be operated for a minimum of five years following installation.« less

Isolation and structural characterisation of two antibacterial free fatty acids from the marine diatom, Phaeodactylum tricornutum.

PubMed

Desbois, Andrew P; Lebl, Tomas; Yan, Liming; Smith, Valerie J

2008-12-01

One solution to the global crisis of antibiotic resistance is the discovery of novel antimicrobial compounds for clinical application. Marine organisms are an attractive and, as yet, relatively untapped resource of new natural products. Cell extracts from the marine diatom, Phaeodactylum tricornutum, have antibacterial activity and the fatty acid, eicosapentaenoic acid (EPA), has been identified as one compound responsible for this activity. During the isolation of EPA, it became apparent that the extracts contained further antibacterial compounds. The present study was undertaken to isolate these additional antibacterial factors using silica column chromatography and reverse-phase high-performance liquid chromatography. Two antibacterial fractions, each containing a pure compound, were isolated and their chemical structures were investigated by mass spectrometry and nuclear magnetic resonance spectroscopy. The antibacterial compounds were identified as the monounsaturated fatty acid (9Z)-hexadecenoic acid (palmitoleic acid; C16:1 n-7) and the relatively unusual polyunsaturated fatty acid (6Z, 9Z, 12Z)-hexadecatrienoic acid (HTA; C16:3 n-4). Both are active against Gram-positive bacteria with HTA further inhibitory to the growth of the Gram-negative marine pathogen, Listonella anguillarum. Palmitoleic acid is active at micro-molar concentrations, kills bacteria rapidly, and is highly active against multidrug-resistant Staphylococcus aureus. These free fatty acids warrant further investigation as a new potential therapy for drug-resistant infections.

Microbial metabolism of tholin

NASA Astrophysics Data System (ADS)

Stoker, C. R.; Boston, P. J.; Mancinelli, R. L.; Segal, W.; Khare, B. N.; Sagan, C.

1990-05-01

In this paper, we show that a wide variety of common soil bacteria are able to obtain their carbon and energy needs from tholin (a class of complex organic heteropolymers thought to be widely distributed through the solar system; in this case tholin was produced by passage of electrical discharge through a mixture of methane, ammonia, and water vapor). We have isolated aerobic, anaerobic, and facultatively anaerobic bacteria which are able to use tholin as a sole carbon source. Organisms which metabolize tholin represent a variety of bacterial genera including Clostridium, Pseudomonas, Bacillus, Acinetobacter, Paracoccus, Alcaligenes, Micrococcus, Cornebacterium, Aerobacter, Arthrobacter, Flavobacterium,and Actinomyces. Aerobic tholin-using bacteria were firrst isolated from soils containing unusual or sparse carbon sources. Some of these organisms were found to be facultatively anaerobic. Strictly anaerobic tholin-using bacteria were isolated from both carbon-rich and carbon-poor anaerobic lake muds. In addition, both aerobic and anaerobic tholin-using bacteria were isolated from common soil collected outside the laboratory building. Some, but not all, of the strains that were able to obtain carbon from tholin were also able to obtain their nitrogen requirements from tholin. Bacteria isolated from common soils were tested for their ability to obtain carbon from the water-soluble fraction, the ethanol-soluble fraction, and the water/ethanol-insoluble fraction of the tholin. Of the 3.5 × 10 7 bacteria isolated per gram of common soils, 1.7 0.5, and 0.2%, respectively, were able to obtaib their carbon requirements from the water-soluble fraction, the ethanol-soluble fraction and the water/ethanol-insoluble fraction of the tholin. The palatability of tholins to modern microbes may have implications for the early evolution of microbial life on Earth. Tholins may have formed the base of the food chain for an early heterotrophic biosphere before the evolution of autotrophy on the early Earth. Where tholins are present on other planets, they could possibly be metabolized by contaminant microorganisms transported to these bodies via spacecraft. Thus, the presence of tholins should be taken into account when evaluating the planetary quarantine requirements for probes to other planets.

Competing epidemics on complex networks

NASA Astrophysics Data System (ADS)

Karrer, Brian; Newman, M. E. J.

2011-09-01

Human diseases spread over networks of contacts between individuals and a substantial body of recent research has focused on the dynamics of the spreading process. Here we examine a model of two competing diseases spreading over the same network at the same time, where infection with either disease gives an individual subsequent immunity to both. Using a combination of analytic and numerical methods, we derive the phase diagram of the system and estimates of the expected final numbers of individuals infected with each disease. The system shows an unusual dynamical transition between dominance of one disease and dominance of the other as a function of their relative rates of growth. Close to this transition the final outcomes show strong dependence on stochastic fluctuations in the early stages of growth, dependence that decreases with increasing network size, but does so sufficiently slowly as still to be easily visible in systems with millions or billions of individuals. In most regions of the phase diagram we find that one disease eventually dominates while the other reaches only a vanishing fraction of the network, but the system also displays a significant coexistence regime in which both diseases reach epidemic proportions and infect an extensive fraction of the network.

Characterization of Two Unique Cholesterol-Rich Lipid Particles Isolated from Human Atherosclerotic Lesions

PubMed Central

Chao, Fei-Fei; Blanchette-Mackie, E. Joan; Chen, Ya-Jun; Dickens, Benjamin F.; Berlin, Elliott; Amende, Lynn M.; Skarlatos, Sonia I.; Gamble, Wilbert; Resau, James H.; Mergner, Wolfgang T.; Kruth, Howard S.

1990-01-01

The authors' laboratory, using histochemicalmethods, previously identified two types of cholesterol-containing lipid particles in the extracellular spaces of human atherosclerotic lesions, one particle enriched in esterified cholesterol and the other particle enriched in unesterified cholesterol. The authors isolated and characterized these lipid particles. The esterified cholesterol-rich lipid particle was a small lipid droplet and differed from intracellular lipid dropletsfound in foam cells with respect to size and chemical composition. It had an esterified cholesterol core surrounded by aphospholipidunesterified cholesterol monolayer. Some aqueous spaces were seen within the particle core. Unesterified cholesterol-rich lipid particles were multilamellated, solid structures and vesicles comprised of single or multiple lamellas. The esterified cholesterol-rich particle had a density <1.01 g/ml, whereas the unesterified cholesterol-rich particle had a density between 1.03 and 1.05 g/ml. Both particles were similar in size fraction, whereas palmitate, stearate, oleate, and linoleate were predominant in the phospholipid fraction. The origins and the role of these two unusual lipid particles in vessel wall cholesterol metabolism remain to be determined. ImagesFigure 1Figure 3Figure 4Figure 5 PMID:2297045

Distribution of materials excavated by the lunar crater Bullialdus and implications for the geologic history of the Nubium region

NASA Technical Reports Server (NTRS)

Tompkins, Stefanie; Pieters, Carle M.; Mustard, John F.; Pinet, Patrick; Chevrel, Serge D.

1994-01-01

Previous spectroscopic studies of the lunar crater Bullialdus, located in the Nubium Basin, indicated an unusual stratigraphy of two gabbroic layers overlying a noritic unit. The possible existence of a layered mafic pluton at Bullialdus was suggested. To investigate the geologic context with more detailed spatial information, charge-coupled device (CCD) images of Bullialdus were obtained using eight filters. A linear mixing model was used to investigate the fractional abundances of spectral end-members chosen from within the multispectral image. Since the reflectance properties of lunar materials over this wavelength range are sensitive to variations in composition and soil maturity, fractional abundance images were used to create a new geologic map of the crater. The spatial relationships of the surface materials confirm the previously inferred stratigraphy, and further reveal the central peaks to exhibit two distinct compositional units: noritic anorthosite and anorthositic norite. Three models for the origin of the observed stratigraphy are considered: Bullialdus has excavated stratigraphic units containing (1) early mare basalt overlying anorthositic-noritic crustal material, (2) part of a layered mafic pluton, and/or (3) part of an impact melt sheet formed by the Nubium Basin impact event.

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.

An Automated High-Throughput System to Fractionate Plant Natural Products for Drug Discovery

PubMed Central

Tu, Ying; Jeffries, Cynthia; Ruan, Hong; Nelson, Cynthia; Smithson, David; Shelat, Anang A.; Brown, Kristin M.; Li, Xing-Cong; Hester, John P.; Smillie, Troy; Khan, Ikhlas A.; Walker, Larry; Guy, Kip; Yan, Bing

2010-01-01

The development of an automated, high-throughput fractionation procedure to prepare and analyze natural product libraries for drug discovery screening is described. Natural products obtained from plant materials worldwide were extracted and first prefractionated on polyamide solid-phase extraction cartridges to remove polyphenols, followed by high-throughput automated fractionation, drying, weighing, and reformatting for screening and storage. The analysis of fractions with UPLC coupled with MS, PDA and ELSD detectors provides information that facilitates characterization of compounds in active fractions. Screening of a portion of fractions yielded multiple assay-specific hits in several high-throughput cellular screening assays. This procedure modernizes the traditional natural product fractionation paradigm by seamlessly integrating automation, informatics, and multimodal analytical interrogation capabilities. PMID:20232897

Modern rather than Mesoarchaean oxidative weathering responsible for the heavy stable Cr isotopic signatures of the 2.95 Ga old Ijzermijn iron formation (South Africa)

NASA Astrophysics Data System (ADS)

Albut, Gülüm; Babechuk, Michael G.; Kleinhanns, Ilka C.; Benger, Manuela; Beukes, Nicolas J.; Steinhilber, Bernd; Smith, Albertus J. B.; Kruger, Stephanus J.; Schoenberg, Ronny

2018-05-01

Previously reported stable Cr isotopic fractionation in Archaean paleosols and iron formations (IFs) have been interpreted as a signature of oxidative weathering of Cr(III) to Cr(VI) in soils, and delivery of isotopically heavy Cr(VI) into the oceans. One of the oldest reported fingerprints of this process is isotopically heavy Cr preserved in the 2.95 Ga old Ijzermijn IF, Sinqeni Formation of the Mozaan Group (Pongola Supergroup), South Africa and could suggest that atmospheric free oxygen was present ca. 600 million years earlier than the Great Oxidation Event (GOE). However, fractionated stable Cr isotopic signatures have only been found to date in surface outcrop samples of the White Mfolozi Inlier exposed along the White Mfolozi River Gorge. In this study, the latter outcrop was resampled along with two drill cores of the Ijzermijn IF and a drill core of the Scotts Hill IF to represent multiple exposures of Mozaan Group IFs with different states of preservation. A detailed geochemical comparison on bulk samples of different units was undertaken using stable Cr isotopes coupled with trace and major elements. Outcrop iron-rich mudstones (Fe - lutites) show very low LOI [wt] %, and very low Fe(II)/Fetot ratios, and lower Ca and Mg relative to equivalent facies in drill cores, indicating the effects that oxidative recent surface weathering had on Fe/Mn-rich carbonate minerals of the IF. Overall rare earth element and yttrium (REE + Y) mixing models agree well with previous studies, confirming that they were minimally disturbed by weathering and are consistent with a high magnitude of continental solutes delivered in a near-shore depositional environment, with a minor contribution of hydrothermally derived fluids that upwelled into shallower depositional setting. Importantly, all drill core samples of this study revealed δ53/52Cr values within the igneous inventory, despite variable amounts of detrital Cr input that includes nearly detritus-free, chert/jasper-rich units. By contrast, a specific group of Fe-lutite samples near the base of White Mfolozi River outcrop bear fractionated Cr isotopic signatures with δ53/52Cr values up to 0.418‰. These outcrop samples also display unusually high U/Th ratios (max. 12.6) as well as enrichments of other elements (W, Tl, As, MREE) that far exceed that observed in correlative drill core units. These observations together with the lack of Cr isotopic fractionation in drill core samples lead us to propose that the heavy δ53/52Cr values of Fe-lutites from outcrop Ijzermijn IF samples reported here and in a previous study are the product of modern oxidative weathering rather than an indicator for Mesoarchaean oxidative weathering at ca. 2.95 Ga.

Cholinephosphotransferase and Diacylglycerol Acyltransferase (Substrate Specificities at a Key Branch Point in Seed Lipid Metabolism).

PubMed

Vogel, G.; Browse, J.

1996-03-01

Many oilseed plants accumulate triacylglycerols that contain unusual fatty acyl structures rather than the common 16- and 18-carbon fatty acids found in membrane lipids of these plants. In vitro experiments demonstrate that triacylglycerols are synthesized via diacylglycerols in microsomal preparations and that this same sub-cellular fraction is the site for the synthesis of phosphatidylcholine, which in seeds is synthesized from diacylglycerol by CDP-choline: diacylglycerol cholinephosphotransferase. In microsomes from Cuphea lanceolata, a plant that accumulates fatty acids with 10 carbons and no double bonds (10:0) in its oil, the diacylglycerol acyltransferase exhibited 4-fold higher activity with 10:0/10:0 molecular species of diacylglycerol than with molecular species containing 18-carbon fatty acids. In castor bean (Ricinus communis), which accumulates oil containing ricinoleic acid, diricinoleoyldiacylglycerol was the favored substrate for triacylglycerol synthesis. In contrast to these modest specificities of the diacylglycerol acyltransferases, the cholinephosphotransferases from these plants and from safflower (Carthamus tinctorius) and rapeseed (Brassica napus) showed little or no specificity across a range of different diacylglycerol substrates. Consideration of these results and other data suggests that the targeting of unusual fatty acids to triacylglycerol synthesis and their exclusion from membrane lipids are not achieved on the basis of the diacylglycerol substrate specificities of the enzymes involved and may instead require the spatial separation of two different diacylglycerol pools.

Cholinephosphotransferase and Diacylglycerol Acyltransferase (Substrate Specificities at a Key Branch Point in Seed Lipid Metabolism).

PubMed Central

Vogel, G.; Browse, J.

1996-01-01

Many oilseed plants accumulate triacylglycerols that contain unusual fatty acyl structures rather than the common 16- and 18-carbon fatty acids found in membrane lipids of these plants. In vitro experiments demonstrate that triacylglycerols are synthesized via diacylglycerols in microsomal preparations and that this same sub-cellular fraction is the site for the synthesis of phosphatidylcholine, which in seeds is synthesized from diacylglycerol by CDP-choline: diacylglycerol cholinephosphotransferase. In microsomes from Cuphea lanceolata, a plant that accumulates fatty acids with 10 carbons and no double bonds (10:0) in its oil, the diacylglycerol acyltransferase exhibited 4-fold higher activity with 10:0/10:0 molecular species of diacylglycerol than with molecular species containing 18-carbon fatty acids. In castor bean (Ricinus communis), which accumulates oil containing ricinoleic acid, diricinoleoyldiacylglycerol was the favored substrate for triacylglycerol synthesis. In contrast to these modest specificities of the diacylglycerol acyltransferases, the cholinephosphotransferases from these plants and from safflower (Carthamus tinctorius) and rapeseed (Brassica napus) showed little or no specificity across a range of different diacylglycerol substrates. Consideration of these results and other data suggests that the targeting of unusual fatty acids to triacylglycerol synthesis and their exclusion from membrane lipids are not achieved on the basis of the diacylglycerol substrate specificities of the enzymes involved and may instead require the spatial separation of two different diacylglycerol pools. PMID:12226231

Distinct effects of boar seminal plasma fractions exhibiting different protein profiles on the functionality of highly diluted boar spermatozoa.

PubMed

García, E M; Calvete, J J; Sanz, L; Roca, J; Martínez, E A; Vázquez, J M

2009-04-01

The aim of this study was to evaluate how different protein profiles of seminal plasma (SP) fractions affect sperm functionality in vitro. Ejaculates from three boars were separated into six fractions. The fractions differed from each other in their sperm content, in their total SP protein content, and their spermadhesin PSP-I/PSP-II and heparin-binding protein (HBP) concentrations. Spermatozoa were mainly recovered in fraction 2 (sperm-rich fraction, >1800 x 10(6) spermatozoa/ml), whereas the pre-sperm fraction 1 and the post-sperm fractions 4-6 contained low numbers of spermatozoa (<500 x 10(6)/ml). Except in fraction 2, the total SP protein concentration and the concentration of both, spermadhesin PSP-I/PSP-II and the HBPs increased with fraction order. Distinct time-dependent effects were observed on motility characteristics and membrane integrity of highly diluted boar spermatozoa upon incubation with a 10% dilution of the SP from each fraction. The highest sperm viability was recorded after exposure for 5 h to fraction 2, followed by fractions 1 and 3. The percentages of motile spermatozoa also differed significantly among fractions after 5 h of incubation. Spermatozoa incubated with SP of fractions 1-3 showed the highest percentage motility. We conclude that different SP fractions exert distinct effects on the functionality of highly diluted boar spermatozoa. Fractions 1-3 appear to promote sperm survival, whereas fractions 4-6 seem to be harmful for preserving the physiological functions of highly diluted boar spermatozoa.

The componential processing of fractions in adults and children: effects of stimuli variability and contextual interference

PubMed Central

Gabriel, Florence C.; Szücs, Dénes

2014-01-01

Recent studies have indicated that people have a strong tendency to compare fractions based on constituent numerators or denominators. This is called componential processing. This study explored whether componential processing was preferred in tasks involving high stimuli variability and high contextual interference, when fractions could be compared based either on the holistic values of fractions or on their denominators. Here, stimuli variability referred to the fact that fractions were not monotonous but diversiform. Contextual interference referred to the fact that the processing of fractions was interfered by other stimuli. To our ends, three tasks were used. In Task 1, participants compared a standard fraction 1/5 to unit fractions. This task was used as a low stimuli variability and low contextual interference task. In Task 2 stimuli variability was increased by mixing unit and non-unit fractions. In Task 3, high contextual interference was created by incorporating decimals into fractions. The RT results showed that the processing patterns of fractions were very similar for adults and children. In task 1 and task 3, only componential processing was utilzied. In contrast, both holistic processing and componential processing were utilized in task 2. These results suggest that, if individuals are presented with the opportunity to perform componential processing, both adults and children will tend to do so, even if they are faced with high variability of fractions or high contextual interference. PMID:25249995

The componential processing of fractions in adults and children: effects of stimuli variability and contextual interference.

PubMed

Zhang, Li; Fang, Qiaochu; Gabriel, Florence C; Szücs, Dénes

2014-01-01

Recent studies have indicated that people have a strong tendency to compare fractions based on constituent numerators or denominators. This is called componential processing. This study explored whether componential processing was preferred in tasks involving high stimuli variability and high contextual interference, when fractions could be compared based either on the holistic values of fractions or on their denominators. Here, stimuli variability referred to the fact that fractions were not monotonous but diversiform. Contextual interference referred to the fact that the processing of fractions was interfered by other stimuli. To our ends, three tasks were used. In Task 1, participants compared a standard fraction 1/5 to unit fractions. This task was used as a low stimuli variability and low contextual interference task. In Task 2 stimuli variability was increased by mixing unit and non-unit fractions. In Task 3, high contextual interference was created by incorporating decimals into fractions. The RT results showed that the processing patterns of fractions were very similar for adults and children. In task 1 and task 3, only componential processing was utilzied. In contrast, both holistic processing and componential processing were utilized in task 2. These results suggest that, if individuals are presented with the opportunity to perform componential processing, both adults and children will tend to do so, even if they are faced with high variability of fractions or high contextual interference.

Diamond and moissanite in ophiolitic mantle rocks and podiform chromitites: A deep carbon source?

NASA Astrophysics Data System (ADS)

Yang, J.; Xu, X.; Wiedenbeck, M.; Trumbull, R. B.; Robinson, P. T.

2010-12-01

Diamonds are known from a variety of occurreces, mainly from mantle-derived kimberlites, meteorite impact craters, and continental deep subduction and collision zones. Recently, an unusual mineral group was discovered in the Luobusa ophiolitic chromitites from the Yarlung Zangbu suture, Tibet, which probably originated from a depth of over 300 km in the mantle. Minerals of deep origin include coesite apparently pseudomorphing stishovite, and diamond as individual grains or inclusions in OsIr alloy. To determine if such UHP and unusual minerals occur elsewhere, we collected about 1.5 t of chromitite from two orebodies in an ultramafic body in the Polar Urals. Thus far, more than 60 different mineral species have been separated from these ores. The most exciting discovery is the common occurrence of diamond, a typical UHP mineral in the Luobusa chromitites. These minerals are very similar in composition and structure to those reported from the Luobusa chromitites. So far diamond and/or moissanite have been discovered from many different ophiolitic ultramafic rocks, including in-situ grains in polished chromitite fragments. These discoveries demonstrate that the Luobusa ophiolite is not a unique diamond-bearing massif. Secondary ion mass spectrometric (SIMS) analysis shows that the ophiolite-hosted diamond has a distinctive 13C-depleted isotopic composition (δ13C from -18 to -28‰, n=70), compatible to the ophiolite-hosted moissanite (δ13C from -18 to -35‰, n=36), both are much lighter than the main carbon reservoir in the upper mantle (δ13C near -5‰). The compiled data from moissanite from kimberlites and other mantle settings share the characteristic of strongly 13C-depleted isotopic composition. This suggests that diamond and moissanite originates from a separate carbon reservoir in the mantle or that its formation involved strong isotopic fractionation. Subduction of biogenic carbonaceous material could potentially satisfy both the unusual isotopic and redox constraints on diamond and moissanite formation, but this material would need to stay chemically isolated from the upper mantle until it reached the high-T stability field of diamond and moissanite. The origin of diamond and moissanite in the mantle is still unsolved, but all evidence from the upper mantle indicates that they cannot have formed there, except under special and local redox conditions. We suggest, alternatively, that diamond and moissanite may have formed in the lower mantle, where the existence of 13C-depleted carbon is strongly suspected.

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.

Extreme emission-line galaxies out to z ~ 1 in zCOSMOS. I. Sample and characterization of global properties

NASA Astrophysics Data System (ADS)

Amorín, R.; Pérez-Montero, E.; Contini, T.; Vílchez, J. M.; Bolzonella, M.; Tasca, L. A. M.; Lamareille, F.; Zamorani, G.; Maier, C.; Carollo, C. M.; Kneib, J.-P.; Le Fèvre, O.; Lilly, S.; Mainieri, V.; Renzini, A.; Scodeggio, M.; Bardelli, S.; Bongiorno, A.; Caputi, K.; Cucciati, O.; de la Torre, S.; de Ravel, L.; Franzetti, P.; Garilli, B.; Iovino, A.; Kampczyk, P.; Knobel, C.; Kovač, K.; Le Borgne, J.-F.; Le Brun, V.; Mignoli, M.; Pellò, R.; Peng, Y.; Presotto, V.; Ricciardelli, E.; Silverman, J. D.; Tanaka, M.; Tresse, L.; Vergani, D.; Zucca, E.

2015-06-01

Context. The study of large and representative samples of low-metallicity star-forming galaxies at different cosmic epochs is of great interest to the detailed understanding of the assembly history and evolution of low-mass galaxies. Aims: We present a thorough characterization of a large sample of 183 extreme emission-line galaxies (EELGs) at redshift 0.11 ≤ z ≤ 0.93 selected from the 20k zCOSMOS bright survey because of their unusually large emission line equivalent widths. Methods: We use multiwavelength COSMOS photometry, HST-ACS I-band imaging, and optical zCOSMOS spectroscopy to derive the main global properties of star-forming EELGs, such as sizes, stellar masses, star formation rates (SFR), and reliable oxygen abundances using both "direct" and "strong-line" methods. Results: The EELGs are extremely compact (r50 ~ 1.3 kpc), low-mass (M∗ ~ 107-1010 M⊙) galaxies forming stars at unusually high specific star formation rates (sSFR ≡ SFR/M⋆ up to 10-7 yr-1) compared to main sequence star-forming galaxies of the same stellar mass and redshift. At rest-frame UV wavelengths, the EELGs are luminous and show high surface brightness and include strong Lyα emitters, as revealed by GALEX spectroscopy. We show that zCOSMOS EELGs are high-ionization, low-metallicity systems, with median 12+log (O/H) = 8.16 ± 0.21 (0.2 Z⊙) including a handful of extremely metal-deficient (<0.1 Z⊙) EELGs. While ~80% of the EELGs show non-axisymmetric morphologies, including clumpy and cometary or tadpole galaxies, we find that ~29% of them show additional low-surface-brightness features, which strongly suggests recent or ongoing interactions. As star-forming dwarfs in the local Universe, EELGs are most often found in relative isolation. While only very few EELGs belong to compact groups, almost one third of them are found in spectroscopically confirmed loose pairs or triplets. Conclusions: The zCOSMOS EELGs are galaxies caught in a transient and probably early period of their evolution, where they are efficiently building up a significant fraction of their present-day stellar mass in an ongoing, galaxy-wide starburst. Therefore, the EELGs constitute an ideal benchmark for comparison studies between low- and high-redshift low-mass star-forming galaxies. Full Tables 1 and 2 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/578/A105

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

Study of the recrystallization in coated pellets - effect of coating on API crystallinity.

PubMed

Nikowitz, Krisztina; Pintye-Hódi, Klára; Regdon, Géza

2013-02-14

Coated diltiazem hydrochloride-containing pellets were prepared using the solution layering technique. Unusual thermal behavior was detected with differential scanning calorimetry (DSC) and its source was determined using thermogravimetry (TG), X-ray powder diffraction (XRPD) and hot-stage microscopy. The coated pellets contained diltiazem hydrochloride both in crystalline and amorphous form. Crystallization occurs on heat treatment causing an exothermic peak on the DSC curves that only appears in pellets containing both diltiazem hydrochloride and the coating. Results indicate that the amorphous fraction is situated in the coating layer. The migration of drugs into the coating layer can cause changes in its degree of crystallinity. Polymeric coating materials should therefore be investigated as possible crystallization inhibitors. Copyright © 2012 Elsevier B.V. All rights reserved.

Prospects of neutral Higgs boson decays in the NMSSM

NASA Astrophysics Data System (ADS)

Almarashi, M. M.

2018-06-01

In this paper, we present the branching ratios of the two lightest CP-even Higgses, h1 and h2 , and the lightest CP-odd Higgs, a1 , in the context of the Next-to-Minimal Supersymmetric Standard Model (NMSSM). We find that for some regions of the parameter space, the branching fractions of a1 into the lightest charginos (a1 → χ1+ χ1-) and neutralinos (a1 → χ1SUP>/0SUP> χ10) are larger than 50 % , and can reach a 100 % level in the latter case. Furthermore, the branching ratio of the h2 →a1a1 can be equal to unity for all h2 masses when it is a pure singlet. The above unusual channels are hallmarks of the existence of the NMSSM.

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.

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-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.

A Candidate Tidal Disruption Event in a Quasar at z = 2.359 from Abundance Ratio Variability

NASA Astrophysics Data System (ADS)

Liu, Xin; Dittmann, Alexander; Shen, Yue; Jiang, Linhua

2018-05-01

A small fraction of quasars show an unusually high nitrogen-to-carbon ratio (N/C) in their spectra. These “nitrogen-rich” (N-rich) quasars are a long-standing puzzle because their interstellar medium implies stellar populations with abnormally high metallicities. It has recently been proposed that N-rich quasars may result from tidal disruption events (TDEs) of stars by supermassive black holes. The rapid enhancement of nitrogen and the depletion of carbon due to the carbon–nitrogen–oxygen cycle in supersolar mass stars could naturally produce high N/C. However, the TDE hypothesis predicts that the N/C should change with time, which has never hitherto been observed. Here we report the discovery of the first N-rich quasar with rapid N/C variability that could be caused by a TDE. Two spectra separated by 1.7 years (rest-frame) show that the N III] λ1750/C III] λ1909 intensity ratio decayed by ∼86% ± 14% (1σ). Optical (rest-frame UV) light-curve and X-ray observations are qualitatively consistent with the TDE hypothesis; though, the time baseline falls short of a definitive proof. Putting the single-object discovery into context, statistical analyses of the ∼80 known N-rich quasars with high-quality archival spectra show evidence (at a 5σ significance level) of a decrease in N/C on timescales of >1 year (rest-frame) and a constant level of ionization (indicated by the C III] λ1909/C IV λ1549 intensity ratio). If confirmed, our results demonstrate the method of identifying TDE candidates in quasars via abundance ratio variability, opening a new window of TDE observations at high redshift (z > 2) with upcoming large-scale time-domain spectroscopic surveys.

Fractionation of 238U/235U by reduction during low temperature uranium mineralisation processes

NASA Astrophysics Data System (ADS)

Murphy, Melissa J.; Stirling, Claudine H.; Kaltenbach, Angela; Turner, Simon P.; Schaefer, Bruce F.

2014-02-01

Investigations of ‘stable’ uranium isotope fractionation during low temperature, redox transformations may provide new insights into the usefulness of the 238U/235U isotope system as a tracer of palaeoredox processes. Sandstone-hosted uranium deposits accumulate at an oxidation/reduction interface within an aquifer from the low temperature reduction of soluble U(VI) complexes in groundwaters, forming insoluble U(IV) minerals. This setting provides an ideal environment in which to investigate the effects of redox transformations on 238U/235U fractionation. Here we present the first coupled measurements of 238U/235U isotopic compositions and U concentrations for groundwaters and mineralised sediment samples from the same redox system in the vicinity of the high-grade Pepegoona sandstone-hosted uranium deposit, Australia. The mineralised sediment samples display extremely variable 238U/235U ratios (herein expressed as δUCRM145238, the per-mil deviation from the international NBL standard CRM145). The majority of mineralised sediment samples have δUCRM145238 values between -1.30±0.05 and 0.55±0.12‰, spanning a ca. 2‰ range. However, one sample has an unusually light isotopic composition of -4.13±0.05‰, which suggests a total range of U isotopic variability of up to ca. 5‰, the largest variation found thus far in a single natural redox system. The 238U/235U isotopic signature of the mineralised sediments becomes progressively heavier (enriched in 238U) along the groundwater flow path. The groundwaters show a greater than 2‰ variation in their 238U/235U ratios, ranging from δUCRM145238 values of -2.39±0.07 to -0.71±0.05‰. The majority of the groundwater data exhibit a clear systematic relationship between 238U/235U isotopic composition and U concentration; samples with the lowest U concentrations have the lowest 238U/235U ratios. The preferential incorporation of 238U during reduction of U(VI) to U(IV) and precipitation of uranium minerals leaves the groundwaters enriched in 235U, resulting in a progressive shift in 238U/235U towards lighter values in the aqueous phase as U is removed. These data can be modelled by a closed system Rayleigh fractionation model, with a fractionation factor (α, representing the 238U/235U composition of the groundwater relative to the solid uranium minerals) ranging from ∼0.9996 to 1.0000, with the majority of datapoints ranging from α values of 0.9998 to 0.9999. The sense and magnitude of the results of this study imply that 238U/235U fractionation is likely to be controlled by volume-dependent nuclear field shift effects during the reduction of U(VI) to U(IV) during mineralisation processes. These findings support the use of the 238U/235U isotopic system as a tracer to constrain the nature and timing of palaeoredox conditions.

Nature and Significance of the High-Sr Aleutian Lavas

NASA Astrophysics Data System (ADS)

Yogodzinski, G. M.; Arndt, S.; Turka, J. R.; Kelemen, P. B.; Vervoort, J. D.; Portnyagin, M.; Hoernle, K.

2011-12-01

Results of the Western Aleutian Volcano Expedition and German-Russian KALMAR cruises include the discovery of seafloor volcanism at the Ingenstrem Depression and at unnamed seamounts 300 km west of Buldir, the westernmost emergent volcano in the Aleutian arc. These discoveries indicate that the surface expression of active Aleutian volcanism goes below sea level just west of Buldir, but is otherwise continuous along the full length of the arc. Many lavas dredged from western Aleutian seamounts are basalts, geochemically similar to basalts from elsewhere in Aleutians and other arcs (La/Yb 4-8, Sr/Y<30, 87Sr/86Sr=0.7031-0.7033). Western Aleutian dredge samples also include high-Sr lavas (>700 ppm Sr), which are mostly plagioclase-hornblende andesites and dacites with low Y and middle-heavy rare-earth elements, fractionated trace element patterns (Sr/Y=50-200, La/Yb=9-25) and MORB-like isotopes (87Sr/86Sr < 0.7028). The endmember Sr-rich lavas are magnesian rhyodacites (SiO2~68%, Mg# >0.65) with 1250-1700 ppm Sr, 4-7 ppm Y, low abundances of all rare-earth elements (La<7 ppm, Yb<0.4 ppm) and 87Sr/86Sr < 0.70266. The high silica and primitive (high Mg#) character of the high-Sr lavas, combined with their strongly fractionated trace element patterns and MORB-like isotopes are consistent with a source predominantly of subducted basalt and a melt residue that contained garnet. The high-Sr lavas have some characteristics of MORB fluids (low Ce/Pb and unradiogenic Pb), and their highly calc-alkaline nature implies high pre-eruptive water contents[1], but low 87Sr/86Sr indicates that their source was in MORB, not seawater-altered MORB. The high-Sr endmember is clearly present in andesites from some emergent volcanoes in the western Aleutians, and mixing arrays indicate that it may be present in all Aleutian lavas (e.g., 87Sr/86Sr vs. La/Yb or Sr/Y); however, radiogenic Pb and Sr from subducted sediment renders the high-Sr endmember isotopically invisible in most central and eastern Aleutian lavas. The geochemistry of small monogenetic sea-floor volcanoes--especially those in the back-arc--may be the best opportunity to identify the high-Sr endmember in central and eastern Aleutian locations. The existence of primitive, high-silica lavas in the western Aleutians, where the subducting plate is probably unusually hot, may also provide key observations toward an improved understanding of high-Mg# andesites and dacites from other hot-slab locations, especially in the Cascades and Central Mexico. [1] Zimmer et al., 2010, J. Petrology, v. 51, p. 2411

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)

Characterization of PM2.5 and identification of transported secondary and biomass burning contribution in Seoul, Korea.

PubMed

Kim, Yumi; Seo, Jihoon; Kim, Jin Young; Lee, Ji Yi; Kim, Hwajin; Kim, Bong Mann

2018-02-01

The chemical and seasonal characteristics of fine particulates in Seoul, Korea, were investigated based on 24-h integrated PM 2.5 measurements made over four 1-month periods in each season between October 2012 and September 2013. The four-season average concentration of PM 2.5 was 37 μg m -3 , and the major chemical components were secondary inorganic aerosol (SIA) species of sulfate, nitrate, and ammonium (49%), followed by organic matter (34%). The mass concentration and most of the chemical components of PM 2.5 showed clear seasonal variation, with a winter-high and summer-low pattern. The winter-to-summer sulfate ratio and the winter organic carbon (OC)-to-elemental carbon (EC) ratio were unusually high compared with those in previous studies. Strong correlations of both the sulfate level and the sulfur oxidation ratio with relative humidity, and between water-soluble OC (WSOC) and SIA in winter, suggest the importance of aqueous phase chemistry for secondary aerosols. A strong correlation between non-sea salt sulfate and Na + levels, a high Cl - /Na + ratio, and an unusual positive correlation between the nitrogen oxidation ratio and temperature during the winter indicate the influence of transported secondary emission sources from upwind urban areas and from China across the Yellow Sea. Despite the absence of local forest fires and the regulation of wood burning, a high levoglucosan concentration and its correlations with OC and WSOC indicate that Seoul was affected by biomass burning sources in the winter. The unusually high water-insoluble OC (WIOC)-to-EC ratio in winter implies additional transported combustion sources of WIOC. The strong correlation between WIOC and levoglucosan suggests the likely influence of transported biomass burning sources on the high WIOC/EC ratio during the winter.

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.

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

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.

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.

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.

Influence of the stringent control system on the transcription of ribosomal ribonucleic acid and ribosomal protein genes in Escherichia coli.

PubMed Central

Dennis, P P

1977-01-01

The fraction of the total ribonucleic acid (RNA) synthesis rate that is messenger RNA (mRNA) for ribosomal protein (r-protein) and ribosomal RNA (rRNA) has been estimated in valS(Ts) rel+ stringent and valS(Ts) relA1 relaxed strains of Escherichia coli during a partial inhibition of valyl-transfer RNA aminoacylation. The partial inhibition was accomplished by shifting the strains from the permissive growth temperature of 29.5 degrees C to the semipermissive temperature of 35.5 degrees C. The RNA synthesized at the elevated temperature was pulse labeled with [3H]uracil. The fraction of the total incorpoarted 3H radioactivity in r-protein mRNA or in rRNA was estimated by specific hybridization to the transducing phages gammaspc1, which carries about 15 r-protein genes and lambdailv5, which carries an rRNA transcription unit. The results clearly demonstrate that the rel gene influences the fraction of the total RNA synthesis rate that is r protein mRNA and rRNA; in the rel+ strain they are significantly increased relative to control cultures. This indicates that the expression of the genes coding for the RNA and protein component of the ribosome are most likely regulated at the level of transcription. Furthermore, it appears that the distribution of functioning RNA polymerase between rRNA genes, r-protein genes, and other types of genes is influenced by the rel gene control system; presumably this influence is mediated through the unusual nucleotide guanosine tetraphosphate. PMID:320185

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 ...

Emergence of recombinant forms in geographic regions with co-circulating HIV subtypes in the dynamic HIV-1 epidemic

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

Zhang, Ming; Letiner, Thomas K; Korber, Bette T

2009-01-01

We have reexamined the subtype designations of {approx}10,000 subtype A, B, C, G, and AG, BC, BF recombinant sequences, and compared the results of the new analysis with their published designations. Intersubtype recombinants dominate HIV epidemics in three different geographical regions. The circulating recombinant from (CRF) CRF02-AG, common in West Central Africa, appears to result from a recombination event that occurred early in the divergence between subtypes A and G, although additional more recent recombination events may have contributed to the breakpoint pattern in this recombinant lineage as well. The Chinese recombinant epidemic strains CRF07 and CRF08, in contrast, resultmore » from recent recombinations between more contemporary strains. Nevertheless, CRF07 and CRF08 contributed to many subsequent recombination events. The BF recombinant epidemics in two HIV-1 epicenters in South America are not independent and BF epidemics in South America have an unusually high fraction of unique recombinant forms (URFs) that have each been found only once and carry distinctive breakpoints. Taken together, these analyses reveal a complex and dynamic picture of the current HIV-1 epidemic, and suggest a means of grouping and tracking relationships between viruses through preservation of shared breakpints.« less

Initial Microstructure Evaluation of a U3Si2 + W Fuel Pin Fabricated Via Arc Melt Gravity Drop Casting

NASA Astrophysics Data System (ADS)

Hoggan, Rita E.; Harp, Jason M.

2018-02-01

Injection casting has historically been used to fabricate metallic nuclear fuel on a large scale. Casting of intermetallic fuel forms, such as U3Si2, may be an alternative pathway for fabrication of fuel pins to powder metallurgy. To investigate casting on a small scale, arc melt gravity drop casting was employed to cast a one-off pin of U3Si2 for evaluation as a fabrication method for U3Si2 as a light water reactor fuel. The pin was sectioned and examined via optical microscopy and scanning electron microscopy equipped with energy dispersive x-ray spectroscopy (EDS). Image analysis was used to estimate the volume fraction of phase impurities as well as porosity. The primary phase determined by EDS was U3Si2 with U-O and U-Si-W phase impurities. Unusually high levels of tungsten were observed because of accidental tungsten introduction during arc melting. No significant changes in microstructure were observed after annealing a section of the pin at 800°C for 72 h. The average density of the sectioned specimens was 12.4 g/cm3 measured via Archimedes principle immersion density and He gas displacement.

Laticiferous taxa as a source of energy and hydrocarbon

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

Marimuthu, S.; Subramanian, R.B.; Kothari, I.L.

Twenty-nine laticiferous taxa of Apocynaceae, Asclepiadaceae, and Sapotaceae were screened for suitability as alternative sources of renewable energy, rubber, and phytochemicals and to select the most promising ones for large-scale cultivation. Of these, Allamanda violacea (14.9% protein, 13.8% polyphenol, 8.6% oil, 3.2% hydrocarbon), Catharanthus roseus (15.4% protein, 10.4% polyphenol, 11.5% oil, 1.9% hydrocarbon), and Holarrhena antidysenterica (14.2% protein, 16.4% polyphenol, 5,4% oil, 4.8% hydrocarbon) of Apocynaceae; Asclepias curassavica (19.3% protein, 6.5% polyphenol, 3.9% oil, 2.0% hydrocarbon), Calotropis gigantea (18.5% protein, 6.8% polyphenol, 7.0% oil, 2.8% hydrocarbon) of Asclepiadaceae; Mimusops elengi (11.3% protein, 9.7% polyphenol, 7.2% oil, 4.0% hydrocarbon) of Sapotaceaemore » show promising potential for future petrochemical plantations; of all these taxa, Holarrhena antidysenterica yielded an unusually high percentage (4.8%) of hydrocarbon fraction followed by Mimusops elengi (4.0%). NMR spectra confirmed the presence of cis-polyisoprene in all species studied except Nerium indicum (white-flowered var.). These data indicate that the majority of the species under investigation may be considered for large-scale cultivation as an alternative source of rubber, intermediate energy, and other phytochemicals.« less

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...

Cannibalism of olivine-rich cumulate xenoliths during the 1998 eruption of Piton de la Fournaise (La Réunion hotspot): Implications for the generation of magma diversity

NASA Astrophysics Data System (ADS)

Salaün, A.; Villemant, B.; Semet, M. P.; Staudacher, T.

2010-12-01

Contrasting with its unusual isotopic homogeneity compared to other hotspot volcanoes, Piton de la Fournaise has produced a large diversity of basaltic magmas over its 0.5 Ma history: picrites and two types of transitional basalts with distinct petrological and chemical compositions. A minor group of evolved basalts (anomalous group of basalts or AGB) is enriched in both compatible (Mg, Fe, Ti, Cr, and Ni) and incompatible (K, Th, and La) elements and depleted in Ca and Si relative to the dominant group of evolved basalts. The 1998 eruption simultaneously produced the two basaltic types at two distinct vents (Hudson vent: AGB, Kapor vent: common basalt) but from the same feeding conduit. Glasses of both magmas are close in composition and belong to the single differentiation trend defined by all 1998-2007 glass compositions. Thermodynamic model (MELTS code) shows that AGB-type magmas cannot be produced by high pressure (> 1 GPa) clinopyroxene fractionation as previously proposed and that all melts of the 1998-2007 activity period are produced by low pressure (< 800 MPa) crystal fractionation from the most primitive basalt (MgO ~ 9%). Modal composition of 1998 lavas (mass balance calculation and SEM image analysis) and olivine crystal composition show that Hudson lavas have assimilated significant fractions of olivine xenocrysts contrary to Kapor lavas. In addition, the higher incompatible element contents of Hudson lavas suggest contamination by a differentiated (trachytic) melt. All AGB share the following characteristics: (i) evolved glass compositions, (ii) 5-10% olivine xenocrysts, and (iii) vents located in a narrow region at the summit of the edifice. They are interpreted as the result of the assimilation of olivine-rich xenoliths either by evolved melts or by basaltic melts contaminated by low fractions of differentiated melts produced from interstitial glass frequently coating cumulates minerals or resulting from partial melting of cumulates bearing pyroxene or plagioclase (wehrlitic to gabbroic cumulates). The scarcity of AGB magmas is attributed to their shallow transfer path in rarely intruded lateral zones of Piton de la Fournaise volcano: wehrlitic to gabbroic cumulates bodies are either heterogeneously distributed within the edifice or have been depleted in low melting point components in the 'Rift Zone' where most of the recent eruptive events are emplaced. These results emphasize the exceptional chemical homogeneity of the primary basaltic melt involved in volcanic activity of Piton de la Fournaise hotspot for 0.5 Ma and the increasingly recognized role of magma-wall rock interactions in erupted magma compositions.

A fatal bite from the burrowing asp Atractaspis corpulenta (Hallowell 1854).

PubMed

Tilbury, Colin R; Verster, Janette

2016-08-01

Bites from the various species of Atractaspis are a common occurrence in Africa but deaths are very unusual. Of the 19 described species, the clinical effects of the bite of only seven have been described, and in only three (Atractaspis irregularis, Atractaspis microlepidota and Atractaspis engaddensis) have fatalities been documented. A case of envenomation is described following a bite to a finger by Atractaspis corpulenta, which resulted in sudden death approximately two and a half hours later. The victim received antivenom and although anaphylaxis to this cannot be ruled out, we consider it to be unlikely to be the cause of death. A late autopsy was performed and the findings and their interpretation are discussed. The previous case fatalities, toxic fractions and clinical effects of Atractaspis venom are briefly reviewed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adrenaline rush: an unusual presentation of phaeochromocytoma.

PubMed

Lindsey, Benjamin; Eisner, Mark David; Mitchell, Hannah Katherine; Clesham, Gerald

2015-08-30

A 44-year-old man presented to the accident and emergency department with chest pain and shortness of breath. Admission ECG revealed ischaemic changes. He had markedly elevated troponin T and a severely impaired left ventricular ejection fraction with regional motion wall abnormalities. He was initially treated in intensive care for acute myocardial infarction. When his renal function improved, an angiogram was performed, which showed unobstructed coronary arteries. He was later found to have a phaeochromocytoma. This case illustrates a rare diagnosis presenting with common symptoms that could easily have been missed. On admission to hospital, patients can easily be labelled with a diagnosis and put on a treatment pathway, such as acute coronary syndrome. It is important for clinicians to keep an open mind and be prepared to review the diagnosis if the history does not fit. 2015 BMJ Publishing Group Ltd.

Adrenaline rush: an unusual presentation of phaeochromocytoma

PubMed Central

Lindsey, Benjamin; Eisner, Mark David; Clesham, Gerald

2015-01-01

A 44-year-old man presented to the accident and emergency department with chest pain and shortness of breath. Admission ECG revealed ischaemic changes. He had markedly elevated troponin T and a severely impaired left ventricular ejection fraction with regional motion wall abnormalities. He was initially treated in intensive care for acute myocardial infarction. When his renal function improved, an angiogram was performed, which showed unobstructed coronary arteries. He was later found to have a phaeochromocytoma. This case illustrates a rare diagnosis presenting with common symptoms that could easily have been missed. On admission to hospital, patients can easily be labelled with a diagnosis and put on a treatment pathway, such as acute coronary syndrome. It is important for clinicians to keep an open mind and be prepared to review the diagnosis if the history does not fit. PMID:26323979

Hybrid Percolation Transition in Cluster Merging Processes: Continuously Varying Exponents

NASA Astrophysics Data System (ADS)

Cho, Y. S.; Lee, J. S.; Herrmann, H. J.; Kahng, B.

2016-01-01

Consider growing a network, in which every new connection is made between two disconnected nodes. At least one node is chosen randomly from a subset consisting of g fraction of the entire population in the smallest clusters. Here we show that this simple strategy for improving connection exhibits a more unusual phase transition, namely a hybrid percolation transition exhibiting the properties of both first-order and second-order phase transitions. The cluster size distribution of finite clusters at a transition point exhibits power-law behavior with a continuously varying exponent τ in the range 2 <τ (g )≤2.5 . This pattern reveals a necessary condition for a hybrid transition in cluster aggregation processes, which is comparable to the power-law behavior of the avalanche size distribution arising in models with link-deleting processes in interdependent networks.

Westerlund 1: monolithic formation of a starburst cluster

NASA Astrophysics Data System (ADS)

Negueruela, Ignacio; Clark, J. Simon; Ritchie, Ben W.; Goodwin, Simon P.

2017-03-01

Westerlund 1 is in all likelihood the most massive young cluster in the Milky Way, with a mass on the order of 105 M ⊙. To determine its bulk properties we have made multi-epoch radial velocity measurements for a substantial fraction of its OB stars and evolved supergiants and obtained multi-object spectroscopy of candidate cluster members in its locale. The results of these two studies show that Westerlund 1 is apparently subvirial and appears completely isolated, with hardly any massive star in its vicinity that could be associated with it in terms of distance modulus or radial velocity. The cluster halo does not extend much further than five parsec away from the centre. All these properties are very unusual among starburst clusters in the Local Universe, which tend to form in the context of large star-forming regions.

Transmission X-ray microscopy (TXM) reveals the nanostructure of a smectite gel.

PubMed

Zbik, Marek S; Martens, Wayde N; Frost, Ray L; Song, Yen-Fang; Chen, Yi-Ming; Chen, Jian-Hua

2008-08-19

The unusual behavior of smectites, the ability to change volume when wetted (swelling) or dried (shrinking), makes soil rich in smectites very unstable and dangerous for the building industry because of the movement of building foundations and poor slope stability. These macroscopic properties are dominated by the structural arrangement of the smectites' finest fraction. Here, we show in three dimensions how the swelling phenomenon in smectite, caused by a combination of hydratation and electrostatic forces, may expand the dry smectite volume not 10-fold, as previously thought, but to more than 1000-fold. A new technique, transmission X-ray microscopy, makes it possible to investigate the internal structure and 3-D tomographic reconstruction of clay aggregates. This reveals, for the first time, the smectite gel arrangement in the voluminous cellular tactoid structure within a natural aqueous environment.

HESS J1943+213: A Non-classical High-frequency-peaked BL Lac Object

NASA Astrophysics Data System (ADS)

Straal, S. M.; Gabányi, K. É.; van Leeuwen, J.; Clarke, T. E.; Dubner, G.; Frey, S.; Giacani, E.; Paragi, Z.

2016-05-01

HESS J1943+213 is an unidentified TeV source that is likely a high-frequency-peaked BL Lac (HBL) object, but that is also compatible with a pulsar wind nebula (PWN) nature. Each of these enormously different astronomical interpretations is supported by some of the observed unusual characteristics. In order to finally classify and understand this object, we took a three-pronged approach, through time-domain, high angular resolution, and multi-frequency radio studies. First, our deep time-domain observations with the Arecibo telescope failed to uncover the putative pulsar powering the proposed PWN. We conclude with ˜70% certainty that HESS J1943+213 does not host a pulsar. Second, long-baseline interferometry of the source with e-MERLIN at 1.5 and 5 GHz shows only a core, that is, a point source at ˜ 1-100 mas resolution. Its 2013 flux density is about one-third lower than that detected in the 2011 observations with similar resolution. This radio variability of the core strengthens the HBL object hypothesis. Third, additional evidence against the PWN scenario comes from the radio spectrum we compiled. The extended structure follows a power-law behavior with spectral index α \\=\\-0.54+/- 0.04 while the core component displays a flat spectrum (α \\=\\-0.03+/- 0.03). In contrast, the radio synchrotron emission of PWNe predicts a single power-law distribution. Overall, we rule out the PWN hypothesis and conclude that the source is a BL Lac object. The consistently high fraction (70%) of the flux density from the extended structure then leads us to conclude that HESS J1943+213 must be a non-classical HBL object.

Spectral imaging and passive sampling to investigate particle sources in urban desert regions.

PubMed

Wagner, Jeff; Casuccio, Gary

2014-07-01

Two types of electron microscopy analyses were employed along with geographic information system (GIS) mapping to investigate potential sources of PM2.5 and PM10 (airborne particulate matter smaller than 2.5 and 10 μm, respectively) in two urbanized desert areas known to exhibit PM excursions. Integrated spectral imaging maps were obtained from scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS) analyses of 13 filters collected in Imperial Valley, California. Seven were from 24 h PM10 Federal Reference Method (FRM) samplers and six were from PM2.5 FRM samplers. This technique enabled extraction of information from particles collected on complex filter matrices, and indicated that all samples exhibited substantial proportions of crustal particles. Six Imperial PM2.5 and PM10 filters selected from unusually high-PM days exhibited more large particles (2.5-15 and 10-30 μm, respectively) than did filters from low-PM days, and were more consistent with soils analyzed from the region. High winds were present on three of the six high-PM days. One of the high-PM2.5 filters also exhibited substantial fine carbonaceous soot PM, suggesting significant contributions from a combustion source. Computer-controlled SEM/EDS (CCSEM/EDS) was conducted on PM collected with UNC Passive samplers from Phoenix, Arizona. The passive samplers showed good agreement with co-located FRM PM10 and PM2.5 measurements (μg m(-3)), and also enabled detailed individual particle analysis. The CCSEM/EDS data revealed mostly crustal particles in both the Phoenix fine and coarse PM10 fractions. GIS maps of multiple dust-related parameters confirm that both Imperial Valley and Phoenix possess favorable conditions for airborne crustal PM from natural and anthropogenic sources.

Phase Curves of WASP-33b and HD 149026b and a New Correlation between Phase Curve Offset and Irradiation Temperature

NASA Astrophysics Data System (ADS)

Zhang, Michael; Knutson, Heather A.; Kataria, Tiffany; Schwartz, Joel C.; Cowan, Nicolas B.; Showman, Adam P.; Burrows, Adam; Fortney, Jonathan J.; Todorov, Kamen; Desert, Jean-Michel; Agol, Eric; Deming, Drake

2018-02-01

We present new 3.6 and 4.5 μm Spitzer phase curves for the highly irradiated hot Jupiter WASP-33b and the unusually dense Saturn-mass planet HD 149026b. As part of this analysis, we develop a new variant of pixel-level decorrelation that is effective at removing intrapixel sensitivity variations for long observations (>10 hr) where the position of the star can vary by a significant fraction of a pixel. Using this algorithm, we measure eclipse depths, phase amplitudes, and phase offsets for both planets at 3.6 and 4.5 μm. 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. We also compare our results to predictions from general circulation models, and we find that while neither planet matches the models well, the discrepancies for HD 149026b are especially 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, heat transport 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 drops with increasing temperature until around 3400 K and rises thereafter. Although some aspects of this trend are mirrored in the circulation models, there are notable differences that provide important clues for future modeling efforts.

N-linked oligosaccharides on the low density lipoprotein receptor homolog SorLA/LR11 are modified with terminal GalNAc-4-SO4 in kidney and brain.

PubMed

Fiete, Dorothy; Mi, Yiling; Oats, Edward L; Beranek, Mary C; Baenziger, Jacques U

2007-01-19

Sorting protein-related receptor (SorLA/LR11) is a highly conserved mosaic receptor that is expressed by cells in a number of different tissues including principal cells of the collecting ducts in the kidney and neurons in the central and peripheral nervous systems. SorLA/LR11 has features that indicate it serves as a sorting receptor shuttling between the plasma membrane, endosomes, and the Golgi. We have found that a fraction of SorLA/LR11 that is synthesized in the kidney and the brain bears N-linked oligosaccharides that are modified with terminal beta1,4-linked GalNAc-4-SO(4). Oligosaccharides located in the vacuolar sorting (Vps) 10p domain (Vps10p domain) are modified with beta1,4-linked GalNAc when the Vps10p domain is expressed in cells along with either of two recently cloned protein-specific beta1,4GalNAc-transferases, GalNAcTIII and GalNAcTIV. Either of two sequences with basic amino acids located within the Vps10p domain is able to mediate recognition by these beta1,4GalNAc-transferases. The highly specific modification of oligosaccharides in the Vps10p domain of SorLA/LR11 with terminal GalNAc-4-SO(4) suggests that this unusual modification may modulate the interaction of SorLA/LR11 with proteins and influence their trafficking.

Geology and 40Ar/39Ar geochronology of the medium- to high-K Tanaga volcanic cluster, western Aleutians

USGS Publications Warehouse

Jicha, Brian R.; Coombs, Michelle L.; Calvert, Andrew T.; Singer, Brad S.

2012-01-01

We used geologic mapping and geochemical data augmented by 40Ar/39Ar dating to establish an eruptive chronology for the Tanaga volcanic cluster in the western Aleutian arc. The Tanaga volcanic cluster is unique in comparison to other central and western Aleutian volcanoes in that it consists of three closely spaced, active, volumetrically significant edifices (Sajaka, Tanaga, and Takawangha), the eruptive products of which have unusually high K2O contents. Thirty-five new 40Ar/39Ar ages obtained in two different laboratories constrain the duration of Pleistocene–Holocene subaerial volcanism to younger than 295 ka. The eruptive activity has been mostly continuous for the last 150 k.y., unlike most other well-characterized arc volcanoes, which tend to grow in discrete pulses. More than half of the analyzed Tanaga volcanic cluster lavas are basalts that have erupted throughout the lifetime of the cluster, although a considerable amount of basaltic andesite and basaltic trachyandesite has also been produced since 200 ka. Major- and trace-element variations suggest that magmas from Sajaka and Tanaga volcanoes are likely to have crystallized pyroxene and/or amphibole at greater depths than the older Takawangha magmas, which experienced a larger percentage of plagioclase-dominated fractionation at shallower depths. Magma output from Takawangha has declined over the last 86 k.y. At ca. 19 ka, the focus of magma flux shifted to the west beneath Tanaga and Sajaka volcanoes, where hotter, more mafic magma erupted.

Platinum-group element geochemistry of the Forest Reef Volcanics, southeastern Australia: Implications for porphyry Au-Cu mineralisation

NASA Astrophysics Data System (ADS)

Lowczak, Jessica N.; Campbell, Ian H.; Cocker, Helen; Park, Jung-Woo; Cooke, David R.

2018-01-01

Platinum-group element concentrations in felsic to intermediate rocks from the Forest Reef Volcanics, Cadia-Neville region, southeastern Australia have been analysed by the Ni-S fire assay-isotope dilution method. The Forest Reef Volcanics are shoshonitic to calc-alkaline in composition and fractionated to produce a wide range of compositions, with MgO varying between 9.7 and 1.8 wt.%. The interest in this suite is that it is coeval with Au-Cu porphyry-style mineralisation in the Cadia mineral district. This study uses PGE geochemistry to determine the timing of sulfide saturation, relative to volatile (ore-fluid) saturation, in the magma that gave rise to the Forest Reef Volcanics and, in turn, to assess how this timing affected the mineralisation potential of the evolving magmatic system. The Forest Reef Volcanics can be subdivided, on the basis of their contrasting PGE geochemistry, into high-Mg (>6.8 wt.% MgO) and low-Mg suites (≤6.8 wt.% MgO). Platinum, Pd and Re concentrations increase in the high-Mg samples, whereas Ir and Ru decrease and Rh concentrations remain steady, with decreasing MgO. The coupled Ir, Ru and Rh depletion is attributed to the partitioning of these elements into magnetite. The rate of Pt and Pd enrichment is not possible by closed-system fractional crystallisation alone, which suggests that the parent magma was replenished by a Pt-Pd-rich melt. In contrast, the PGE concentrations in the low-Mg samples decrease with decreasing MgO indicating the onset of sulfide saturation at 6.8 wt.% MgO, which is confirmed by the presence of spheroidal sulfide inclusions in liquidus crystals (i.e. clinopyroxene, plagioclase, magnetite). The rate of Pd depletion is appreciably less than for any other sulfide saturated felsic system for which data are available. This requires either that the amount of sulfide melt to have precipitated was unusually low, or that the rate of Pd depletion was limited by the mass of silicate melt the sulfide melt reached equilibrium with, or both. In any event, the fraction of sulfide melt that precipitated was too small to have had a significant effect on the Cu and Au content of the magma so that both Cu and Au were available to enter the ore-forming fluid when the magma became volatile saturated at, or shortly after, it reached ca. 2.9 wt.% MgO.

A Philippinite with an Unusually Large Bubble: Gas Pressure and Noble Gas Composition

NASA Astrophysics Data System (ADS)

Matsuda, J.; Maruoka, T.; Pinti, D. L.; Koeberl, C.

1995-09-01

Bubbles are common in tektites, but usually their sizes range up to only a few mm. They are most abundant in Muong Nong-type tektites. The gases contained in these bubbles are of terrestrial atmospheric composition, with pressures below 1 atm (e.g., [1]). The abundances of light noble gases (He, Ne) are controlled by diffusion from the atmosphere [2], and noble gases dissolved in tektite glass indicate that the glass solidified at atmospheric pressures equivalent to about 40 km altitude [3]. Large bubbles in splash-form tektites are rather rare. Thus, the finding that a philippinite (size: 6.0 x 4.5 cm; weight: 199.6 g) contains an unusually large bubble justified a detailed study. The volume of the bubble, which was confirmed by X-ray photography, was estimated at 5.4 cm^3, by comparing the density of this tektite (2.288 g/cm^3) to that of normal philippinites (2.438 g/cm^3). A device was specifically constructed for crushing the present sample under vacuum. The 10x10 cm cylindrical device has a piston that allows to gently crush the sample by turning a handle. Various disk spacers can be used to adjust the inner height to that of the sample. The device is made of stainless steel, yielding a low noble gas blank. The crushing device is connected to a purification line and a noble gas sector-type mass spectrometer (VG 5400) [4]. Before crushing, the complete tektite was wrapped in aluminum foil. A first crushing attempt, using stainless steel disk spacers, failed and resulted in damage to the steel spacers, indicating a high strength of the tektite. Using iron disk spacers resulted in an ambient pressure increase (probably due to hydrogen from the Fe) in the sample chamber. However, the noble gas blanks were negligible. The background pressure, at 2 x 10-4 Torr, increased to 3 x 10-4 Torr when the sample was crushed. From the volume of the crushing device and that of the bubble in the tektite, the total gas pressure in the bubble was estimated at about 1 x 10-4 atm. Part of the extracted gas was kept for total gas analysis, while the remainder has been purified for the noble gas measurements. Total amounts and isotopic ratios of all noble gases were measured. The amounts of Ar, Kr, and Xe close to the blank level, while those of He and Ne were about 3 to 4 orders of magnitude larger than the blank. The ^20Ne/^36Ar ratio in the bubble gas is more than 4 orders of magnitude higher than the atmospheric value, which is similar to the pattern previously observed in tektites [2,3,5]. The isotopic ratios of Ar, Kr and Xe were, within uncertainties, similar to those of the terrestrial atmosphere. However, the Ne isotopic ratios were significantly different from atmospheric values, and differ from the results reported in previous studies [2,5]. The Ne isotope data seem to lie on the mass fractionation line from the atmosphere in a ^20Ne/^22Ne vs. ^21Ne/^22Ne three isotope plot, suggesting that the Ne in the bubble has diffused in from the atmosphere. However, it is generally believed that the isotopic fractionation during a steady state is very small, and the observed Ne values are higher than those calculated from simple mass fractionation [6]. The high isotopic fractionation is likely to be associated with the non-equilibrium conditions prevailing during tektite formation. Acknowledgments: We are grateful to D. Heinlein for bringing the precious sample to our attention and for allowing its analysis. References: [1] Jessberger E. K. and Gentner W. (1972) EPSL, 14, 221-225. [2] Matsubara K. and Matsuda J. (1991) Meteoritics, 26, 217-220. [3] Matsuda J. et al. (1993) Meteoritics, 28, 586-599. [4] Maruoka T. and Matsuda J. (1995) J. Mass Spectrom. Soc. Jpn., 43, 1-8. [5] Hennecke et al. (1975) JGR, 80, 2931-2934. [6] Kaneoka I., EPSL, 48, 284-292.

Petrology of Hualalai volcano, Hawaii: Implication for mantle composition

USGS Publications Warehouse

Clague, D.A.; Jackson, E.D.; Wright, T.L.

1980-01-01

Hualalai is one of five volcanoes whose eruptions built the island of Hawaii. The historic 1800-1801 flows and the analyzed prehistoric flows exposed at the surface are alkalic basalts except for a trachyte cone and flow at Puu Waawaa and a trachyte maar deposit near Waha Pele. The 1800-1801 eruption produced two flows: the upper Kaupulehu flow and the lower Huehue flow. The analyzed lavas of the two 1800-1801 flows are geochemically identical with the exception of a few samples from the toe of the Huehue flow that appear to be derived from a separate magmatic batch. The analyzed prehistoric basalts are nearly identical to the 1800-1801 flows but include some lavas that have undergone considerable shallow crystal fractionation. The least fractionated alkalic basalts from Hualalai are in equilibrium with mantle olivine (Fo87) indicating that the Hawaiian mantle source region is not unusually iron-rich. The 1800-1801 and analyzed prehistoric basalts can be generated by about 5-10% partial fusion of a garnet-bearing source relatively enriched in the light-rare-earths. The mantle underlying the Hawaiian Islands is chemically and mineralogically heterogeneous before and after extraction of the magmas that make up the volcanoes. ?? 1980 Intern. Association of Volcanology and Chemistry of the Earth's Interior.

Exerting control over the helical chirality in the main chain of sergeants-and-soldiers-type poly(quinoxaline-2,3-diyl)s by changing from random to block copolymerization protocols.

PubMed

Nagata, Yuuya; Nishikawa, Tsuyoshi; Suginome, Michinori

2015-04-01

Chiral random poly(quinoxaline-2,3-diyl) polymers of the sergeants-and-soldiers-type (sergeant units bearing (S)-3-octyloxymethyl groups) adopt an M- or P-helical conformation in the presence of achiral units bearing propoxymethyl or butoxy groups (soldier units), respectively. Unusual bidirectional induction of the helical sense can be observed for a copolymer with butoxy soldier units upon changing the mole fraction of the sergeant units. In the presence of 16-20% of sergeant units, the selective induction of a P-helix was observed, while the selective induction of an M-helix was observed for a mole fraction of sergeant units of more than 60%. This phenomenon could be successfully employed to control the helical chirality of copolymers by applying either random or block copolymerization protocols. Random or block copolymerization of sergeant and soldier monomers in a 18:82 ratio resulted in the formation of 250mers with almost absolute P- or M-helical conformation, respectively (>99% ee). Incorporation of a small amount of coordination sites into the random and block copolymers resulted in chiral macromolecular ligands, which allowed the enantioselective synthesis of both enantiomers in the Pd-catalyzed asymmetric hydrosilylation of β-methylstyrene.

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...

Performance enhancement of direct ethanol fuel cell using Nafion composites with high volume fraction of titania

NASA Astrophysics Data System (ADS)

Matos, B. R.; Isidoro, R. A.; Santiago, E. I.; Fonseca, F. C.

2014-12-01

The present study reports on the performance enhancement of direct ethanol fuel cell (DEFC) at 130 °C with Nafion-titania composite electrolytes prepared by sol-gel technique and containing high volume fractions of the ceramic phase. It is found that for high volume fractions of titania (>10 vol%) the ethanol uptake of composites is largely reduced while the proton conductivity at high-temperatures is weakly dependent on the titania content. Such tradeoff between alcohol uptake and conductivity resulted in a boost of DEFC performance at high temperatures using Nafion-titania composites with high fraction of the inorganic phase.

The role of macromolecular crowding in the evolution of lens crystallins with high molecular refractive index.

PubMed

Zhao, Huaying; Magone, M Teresa; Schuck, Peter

2011-08-01

Crystallins are present in the lens at extremely high concentrations in order to provide transparency and generate a high refractive power of the lens. The crystallin families prevalent in the highest density lens tissues are γ-crystallins in vertebrates and S-crystallins in cephalopods. As shown elsewhere, in parallel evolution, both have evolved molecular refractive index increments 5-10% above those of most proteins. Although this is a small increase, it is statistically very significant and can be achieved only by very unusual amino acid compositions. In contrast, such a molecular adaptation to aid in the refractive function of the lens did not occur in crystallins that are preferentially located in lower density lens tissues, such as vertebrate α-crystallin and taxon-specific crystallins. In the current work, we apply a model of non-interacting hard spheres to examine the thermodynamic contributions of volume exclusion at lenticular protein concentrations. We show that the small concentration decrease afforded by the higher molecular refractive index increment of crystallins can amplify nonlinearly to produce order of magnitude differences in chemical activities, and lead to reduced osmotic pressure and the reduced propensity for protein aggregation. Quantitatively, this amplification sets in only at protein concentrations as high as those found in hard lenses or the nucleus of soft lenses, in good correspondence to the observed crystallin properties in different tissues and different species. This suggests that volume exclusion effects provide the evolutionary driving force for the unusual refractive properties and the unusual amino acid compositions of γ-crystallins and S-crystallins.

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.

The role of macromolecular crowding in the evolution of lens crystallins with high molecular refractive index

PubMed Central

Zhao, Huaying; Magone, M. Teresa; Schuck, Peter

2011-01-01

Crystallins are present in the lens at extremely high concentrations in order to provide transparency and generate a high refractive power of the lens. The crystallin families prevalent in the highest density lens tissues are γ crystallins in vertebrates and S crystallins in cephalopods. In parallel evolution, both have evolved molecular refractive index increments 5 – 10 % above those of most proteins. Although this is a small increase, it is statistically very significant and can be achieved only by very unusual amino acid compositions. In contrast, such a molecular adaptation to aid in the refractive function of the lens did not occur in crystallins that are preferentially located in lower density lens tissues, such as vertebrate α crystallin and taxon specific crystallins. In the current work, we apply a model of non-interacting hard spheres to examine the thermodynamic contributions of volume exclusion at lenticular protein concentrations. We show that the small concentration decrease afforded by the higher molecular refractive index increment of crystallins can amplify nonlinearly to produce order of magnitude differences in chemical activities, and lead to reduced osmotic pressure and the reduced propensity for protein aggregation. Quantitatively, this amplification sets in only at protein concentrations as high as those found in hard lenses or the nucleus of soft lenses, in good correspondence to the observed crystalline properties in different tissues and different species. This suggests that volume exclusion effects provide the evolutionary driving force for the unusual refractive properties and the unusual amino acid compositions of γ crystallins and S crystallins. PMID:21566271

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.

Effects of alkalinity and salinity at low and high light intensity on hydrogen isotope fractionation of long-chain alkenones produced by Emiliania huxleyi

NASA Astrophysics Data System (ADS)

Weiss, Gabriella M.; Pfannerstill, Eva Y.; Schouten, Stefan; Sinninghe Damsté, Jaap S.; van der Meer, Marcel T. J.

2017-12-01

Over the last decade, hydrogen isotopes of long-chain alkenones have been shown to be a promising proxy for reconstructing paleo sea surface salinity due to a strong hydrogen isotope fractionation response to salinity across different environmental conditions. However, to date, the decoupling of the effects of alkalinity and salinity, parameters that co-vary in the surface ocean, on hydrogen isotope fractionation of alkenones has not been assessed. Furthermore, as the alkenone-producing haptophyte, Emiliania huxleyi, is known to grow in large blooms under high light intensities, the effect of salinity on hydrogen isotope fractionation under these high irradiances is important to constrain before using δDC37 to reconstruct paleosalinity. Batch cultures of the marine haptophyte E. huxleyi strain CCMP 1516 were grown to investigate the hydrogen isotope fractionation response to salinity at high light intensity and independently assess the effects of salinity and alkalinity under low-light conditions. Our results suggest that alkalinity does not significantly influence hydrogen isotope fractionation of alkenones, but salinity does have a strong effect. Additionally, no significant difference was observed between the fractionation responses to salinity recorded in alkenones grown under both high- and low-light conditions. Comparison with previous studies suggests that the fractionation response to salinity in culture is similar under different environmental conditions, strengthening the use of hydrogen isotope fractionation as a paleosalinity proxy.

The Hydrothermal System at Home Plate in Gusev Crater, Mars: Formation of High Silica Material by Acid-Sulfate Alteration of Basalt

NASA Technical Reports Server (NTRS)

Morris, R. V.; Ming, D. W.; Gellert, R.; Yen, A.; Clark, B. C.; Gnaff, T. G.; Arvidson, R. E.; Squyres, S. W.

2008-01-01

The Alpha Particle X-ray Spectrometer (APXS) instrument on the Mars Exploration Rover (MER) Spirit measured three targets on or adjacent to Home Plate in Gusev Crater that have unusually high SiO2 concentrations (68% to 91%), unusually low FeO concentrations (1% to 7%, with total Fe as FeO), and unusually high TiO2/FeO ratios (0.2 to 1.2 by weight) [1]. Two targets (Kenosha Comets and Lefty Ganote) are located on high albedo soil (Gertrude Weise) that was exposed by the rover wheels, and one target is a float rock called Fuzzy Smith. Kenosha Comets has the highest SiO2 concentration, lowest FeO concentration, and highest TiO2/FeO ratio. Mineralogical evidence from the MER Miniature Thermal Emission Spectrometer (Mini-TES) suggests that the SiO2 is present as amorphous (noncrystalline) SiO2 at Gertrude Weise and nearby targets [2,3]. Mini-TES data were not acquired for Fuzzy Smith. Home Plate is considered to have an explosive volcanic origin, resulting when basaltic magma came into contact with ground water or ice [4]. Within 50 m to 1 km of Home Plate are sulfate rich soil deposits (Paso Robles class soils with 22-35% SO3) which are considered to be probable fumarolic and/or hydrothermal deposits associated with the volcanism [5]. We develop the model here, suggested by [5], that the high-silica materials are another manifestation of acid-sulfate processes associated with fumarolic and hydrothermal activity at Home Plate. This is done by analogy with basaltic materials altered by acid sulfate processes on the Island of Hawaii.

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.

Stable Isotope Signatures of Middle Palaeozoic Ahermatypic Rugose Corals - Deciphering Secondary Alteration, Vital Fractionation Effects, and Palaeoecological Implications.

PubMed

Jakubowicz, Michal; Berkowski, Blazej; López Correa, Matthias; Jarochowska, Emilia; Joachimski, Michael; Belka, Zdzislaw

2015-01-01

This study investigates stable isotope signatures of five species of Silurian and Devonian deep-water, ahermatypic rugose corals, providing new insights into isotopic fractionation effects exhibited by Palaeozoic rugosans, and possible role of diagenetic processes in modifying their original isotopic signals. To minimize the influence of intraskeletal cements on the observed signatures, the analysed specimens included unusual species either devoid of large intraskeletal open spaces ('button corals': Microcyclus, Palaeocyclus), or typified by particularly thick corallite walls (Calceola). The corals were collected at four localities in the Holy Cross Mountains (Poland), Mader Basin (Morocco) and on Gotland (Sweden), representing distinct diagenetic histories and different styles of diagenetic alteration. To evaluate the resistance of the corallites to diagenesis, we applied various microscopic and trace element preservation tests. Distinct differences between isotopic compositions of the least-altered and most-altered skeleton portions emphasise a critical role of material selection for geochemical studies of Palaeozoic corals. The least-altered parts of the specimens show marine or near-marine stable isotope signals and lack positive correlation between δ13C and δ18O. In terms of isotopic fractionation mechanisms, Palaeozoic rugosans must have differed considerably from modern deep-water scleractinians, typified by significant depletion in both 18O and 13C, and pronounced δ13C-δ18O co-variance. The fractionation effects exhibited by rugosans seem similar rather to the minor isotopic effects typical of modern non-scleractinian corals (octocorals and hydrocorals). The results of the present study add to growing evidence for significant differences between Scleractinia and Rugosa, and agree with recent studies indicating that calcification mechanisms developed independently in these two groups of cnidarians. Consequently, particular caution is needed in using scleractinians as analogues in isotopic studies of extinct coral lineages. Answering some of the pertinent palaeoecological questions, such as that of the possibility of photosymbiosis in Palaeozoic corals, may not be possible based on stable isotope data.

The contribution of water soluble and water insoluble organic fractions to oxygen uptake rate during high rate composting.

PubMed

Giuliana, D'Imporzano; Fabrizio, Adani

2007-02-01

This study aims to establish the contribution of the water soluble and water insoluble organic fractions to total oxygen uptake rate during high rate composting process of a mixture of organic fraction of municipal solid waste and lignocellulosic material. This mixture was composted using a 20 l self-heating pilot scale composter for 250 h. The composter was fully equipped to record both the biomass-temperature and oxygen uptake rate. Representative compost samples were taken at 0, 70, 100, 110, 160, and 250 h from starting time. Compost samples were fractionated in water soluble and water insoluble fractions. The water soluble fraction was then fractionated in hydrophilic, hydrophobic, and neutral hydrophobic fractions. Each fraction was then studied using quantitative (total organic carbon) and qualitative analysis (diffuse reflectance infrared spectroscopy and biodegradability test). Oxygen uptake rates were high during the initial stages of the process due to rapid degradation of the soluble degradable organic fraction (hydrophilic plus hydrophobic fractions). Once this fraction was depleted, polymer hydrolysis accounted for most of the oxygen uptake rate. Finally, oxygen uptake rate could be modeled using a two term kinetic. The first term provides the oxygen uptake rate resulting from the microbial growth kinetic type on easily available, no-limiting substrate (soluble fraction), while the second term considers the oxygen uptake rate caused by the degradation of substrate produced by polymer hydrolysis.

Comparison of rumen bacteria distribution in original rumen digesta, rumen liquid and solid fractions in lactating Holstein cows.

PubMed

Ji, Shoukun; Zhang, Hongtao; Yan, Hui; Azarfar, Arash; Shi, Haitao; Alugongo, Gibson; Li, Shengli; Cao, Zhijun; Wang, Yajing

2017-01-01

Original rumen digesta, rumen liquid and solid fractions have been frequently used to assess the rumen bacterial community. However, bacterial profiles in rumen original digesta, liquid and solid fractions vary from each other and need to be better established. To compare bacterial profiles in each fraction, samples of rumen digesta from six cows fed either a high fiber diet (HFD) or a high energy diet (HED) were collected via rumen fistulas. Rumen digesta was then squeezed through four layers of cheesecloth to separate liquid and solid fractions. The bacterial profiles of rumen original digesta, liquid and solid fractions were analyzed with High-throughput sequencing technique. Rumen bacterial diversity was mainly affected by diet and individual cow ( P  > 0.05) rather than rumen fraction. Bias distributed bacteria were observed in solid and liquid fractions of rumen content using Venn diagram and LEfSe analysis. Fifteen out of 16 detected biomarkers (using LEfSe analysis) were found in liquid fraction, and these 15 biomarkers contributed the most to the bacterial differences among rumen content fractions. Similar results were found when using samples of original rumen digesta, rumen liquid or solid fractions to assess diversity of rumen bacteria; however, more attention should be draw onto bias distributed bacteria in different ruminal fractions, especially when liquid fraction has been used as a representative sample for rumen bacterial study.

Rhenium-osmium isotope and highly-siderophile-element abundance systematics of angrite meteorites

NASA Astrophysics Data System (ADS)

Riches, Amy J. V.; Day, James M. D.; Walker, Richard J.; Simonetti, Antonio; Liu, Yang; Neal, Clive R.; Taylor, Lawrence A.

2012-11-01

Coupled 187Os/188Os compositions and highly-siderophile-element (HSE: Os, Ir, Ru, Pt, Pd, and Re) abundance data are reported for eight angrite achondrite meteorites that include quenched- and slowly-cooled textural types. These data are combined with new major- and trace-element concentrations determined for bulk-rock powder fractions and constituent mineral phases, to assess angrite petrogenesis. Angrite meteorites span a wide-range of HSE abundances from <0.005 ppb Os (e.g., Northwest Africa [NWA] 1296; Angra dos Reis) to >100 ppb Os (NWA 4931). Chondritic to supra-chondritic 187Os/188Os (0.1201-0.2127) measured for Angra dos Reis and quenched-angrites correspond to inter- and intra-sample heterogeneities in Re/Os and HSE abundances. Quenched-angrites have chondritic-relative rare-earth-element (REE) abundances at 10-15×CI-chondrite, and their Os-isotope and HSE abundance variations represent mixtures of pristine uncontaminated crustal materials that experienced addition (<0.8%) of exogenous chondritic materials during or after crystallization. Slowly-cooled angrites (NWA 4590 and NWA 4801) have fractionated REE-patterns, chondritic to sub-chondritic 187Os/188Os (0.1056-0.1195), as well as low-Re/Os (0.03-0.13), Pd/Os (0.071-0.946), and relatively low-Pt/Os (0.792-2.640). Sub-chondritic 187Os/188Os compositions in NWA 4590 and NWA 4801 are unusual amongst planetary basalts, and their HSE and REE characteristics may be linked to melting of mantle sources that witnessed prior basaltic melt depletion. Angrite HSE-Yb systematics suggest that the HSE behaved moderately-incompatibly during angrite magma crystallization, implying the presence of metal in the crystallizing assemblage. The new HSE abundance and 187Os/188Os compositions indicate that the silicate mantle of the angrite parent body(ies) (APB) had HSE abundances in chondritic-relative proportions but at variable abundances at the time of angrite crystallization. The HSE systematics of angrites are consistent with protracted post-core formation accretion of materials with chondritic-relative abundances of HSE to the APB, and these accreted materials were rapidly, yet inefficiently, mixed into angrite magma source regions early in Solar System history.

The evolution of 1 AU equatorial solar wind and its association with the morphology of the heliospheric current sheet from solar cycles 23 to 24

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

Zhao, L.; Landi, E.; Zurbuchen, T. H.

2014-09-20

The solar wind can be categorized into three types based on its 'freeze-in' temperature (T {sub freeze-in}) in the coronal source: low T {sub freeze-in} wind mostly from coronal holes, high T {sub freeze-in} wind mostly from regions outside of coronal holes, including streamers (helmet streamer and pseudostreamer), active regions, etc., and transient interplanetary coronal mass ejections (ICMEs) usually possessing the hottest T {sub freeze-in}. The global distribution of these three types of wind has been investigated by examining the most effective T {sub freeze-in} indicator, the O{sup 7+}/O{sup 6+} ratio, as measured by the Solar Wind Ion Composition Spectrometermore » on board the Advanced Composition Explorer (ACE) during 1998-2008 by Zhao et al. In this study, we extend the previous investigation to 2011 June, covering the unusual solar minimum between solar cycles 23 and 24 (2007-2010) and the beginning of solar cycle 24. We find that during the entire solar cycle, from the ascending phase of cycle 23 in 1998 to the ascending phase of cycle 24 in 2011, the average fractions of the low O{sup 7+}/O{sup 6+} ratio (LOR) wind, the high O{sup 7+}/O{sup 6+} ratio (HOR) wind, and ICMEs at 1 AU are 50.3%, 39.4%, and 10.3%, respectively; the contributions of the three types of wind evolve with time in very different ways. In addition, we compare the evolution of the HOR wind with two heliospheric current sheet (HCS) parameters, which indicate the latitudinal standard deviation (SD) and the slope (SL) of the HCS on the synoptic Carrington maps at 2.5 solar radii surface. We find that the fraction of HOR wind correlates with SD and SL very well (slightly better with SL than with SD), especially after 2005. This result verifies the link between the production of HOR wind and the morphology of the HCS, implying that at least one of the major sources of the HOR wind must be associated with the HCS.« less

The unusual ISM in Blue and Dusty Gas Rich Galaxies (BADGRS).

NASA Astrophysics Data System (ADS)

Dunne, L.; Zhang, Z.; De Vis, P.; Clark, C. J. R.; Oteo, I.; Maddox, S. J.; Cigan, P.; de Zotti, G.; Gomez, H. L.; Ivison, R. J.; Rowlands, K.; Smith, M. W. L.; van der Werf, P.; Vlahakis, C.; Millard, J. S.

2018-06-01

The Herschel-ATLAS unbiased survey of cold dust in the local Universe is dominated by a surprising population of very blue (FUV - K < 3.5), dust-rich galaxies with high gas fractions ({f_{HI}=M_{HI}/({ M_{\\ast }}+M_{HI})}>0.5). Dubbed `Blue and Dusty Gas Rich Sources' (BADGRS) they have cold diffuse dust temperatures, and the highest dust-to-stellar mass ratios of any galaxies in the local Universe. Here, we explore the molecular ISM in a representative sample of BADGRS, using very deep {CO(J_{up}=1,2,3)} observations across the central and outer disk regions. We find very low CO brightnesses (Tp = 5 - 30 mK), despite the bright far-infrared emission and metallicities in the range 0.5 < Z/Z⊙ < 1.0. The CO line ratios indicate a range of conditions with R_{21}={T_b^{21}/T_b^{10}=0.6-2.1} and R_{31}={T_b^{32}/T_b^{10}=0.2-1.2}. Using a metallicity dependent conversion from CO luminosity to molecular gas mass we find M_{H2}/{M_d}˜ 7-27 and Σ _{H2} = 0.5-6 M_{⊙} {pc^{-2}}, around an order of magnitude lower than expected. The BADGRS have lower molecular gas depletion timescales (τd ˜ 0.5 Gyr) than other local spirals, lying offset from the Kennicutt-Schmidt relation by a similar factor to Blue Compact Dwarf galaxies. The cold diffuse dust temperature in BADGRS (13-16 K) requires an interstellar radiation field 10-20 times lower than that inferred from their observed surface brightness. We speculate that the dust in these sources has either a very clumpy geometry or a very different opacity in order to explain the cold temperatures and lack of CO emission. BADGRS also have low UV attenuation for their UV colour suggestive of an SMC-type dust attenuation curve, different star formation histories or different dust/star geometry. They lie in a similar part of the IRX-β space as z ˜ 5 galaxies and may be useful as local analogues for high gas fraction galaxies in the early Universe.

THE ARECIBO LEGACY FAST ALFA SURVEY: THE GALAXY POPULATION DETECTED BY ALFALFA

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

Huang, Shan; Haynes, Martha P.; Giovanelli, Riccardo

Making use of H I 21 cm line measurements from the ALFALFA survey ({alpha}.40) and photometry from the Sloan Digital Sky Survey (SDSS) and Galaxy Evolution Explorer (GALEX), we investigate the global scaling relations and fundamental planes linking stars and gas for a sample of 9417 common galaxies: the {alpha}.40-SDSS-GALEX sample. In addition to their H I properties derived from the ALFALFA data set, stellar masses (M{sub *}) and star formation rates (SFRs) are derived from fitting the UV-optical spectral energy distributions. 96% of the {alpha}.40-SDSS-GALEX galaxies belong to the blue cloud, with the average gas fraction f{sub HI} {identical_to}more » M{sub HI}/M{sub *} {approx} 1.5. A transition in star formation (SF) properties is found whereby below M{sub *} {approx} 10{sup 9.5} M{sub Sun }, the slope of the star-forming sequence changes, the dispersion in the specific star formation rate (SSFR) distribution increases, and the star formation efficiency (SFE) mildly increases with M{sub *}. The evolutionary track in the SSFR-M{sub *} diagram, as well as that in the color-magnitude diagram, is linked to the H I content; below this transition mass, the SF is regulated strongly by the H I. Comparison of H I and optically selected samples over the same restricted volume shows that the H I-selected population is less evolved and has overall higher SFR and SSFR at a given stellar mass, but lower SFE and extinction, suggesting either that a bottleneck exists in the H I-to-H{sub 2} conversion or that the process of SF in the very H I-dominated galaxies obeys an unusual, low-efficiency SF law. A trend is found that, for a given stellar mass, high gas fraction galaxies reside preferentially in dark matter halos with high spin parameters. Because it represents a full census of H I-bearing galaxies at z {approx} 0, the scaling relations and fundamental planes derived for the ALFALFA population can be used to assess the H I detection rate by future blind H I surveys and intensity mapping experiments at higher redshift.« less

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…

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.

Effect of hydrogen limitation and temperature on the fractionation of sulfur isotopes by a deep-sea hydrothermal vent sulfate-reducing bacterium

NASA Astrophysics Data System (ADS)

Hoek, Joost; Reysenbach, Anna-Louise; Habicht, Kirsten S.; Canfield, Donald E.

2006-12-01

The fractionation of sulfur isotopes by the thermophilic chemolithoautotrophic Thermodesulfatator indicus was explored during sulfate reduction under excess and reduced hydrogen supply, and the full temperature range of growth (40-80 °C). Fractionation of sulfur isotopes measured under reduced H 2 conditions in a fed-batch culture revealed high fractionations (24-37‰) compared to fractionations produced under excess H 2 supply (1-6‰). Higher fractionations correlated with lower sulfate reduction rates. Such high fractionations have never been reported for growth on H 2. For temperature-dependant fractionation experiments cell-specific rates of sulfate reduction increased with increasing temperatures to 70 °C after which sulfate-reduction rates rapidly decreased. Fractionations were relatively high at 40 °C and decreased with increasing temperature from 40-60 °C. Above 60 °C, fractionation trends switched and increased again with increasing temperatures. These temperature-dependant fractionation trends have not previously been reported for growth on H 2 and are not predicted by a generally accepted fractionation model for sulfate reduction, where fractionations are controlled as a function of temperature, by the balance of the exchange of sulfate across the cell membrane, and enzymatic reduction rates of sulfate. Our results are reproduced with a model where fractionation is controlled by differences in the temperature response of enzyme reaction rates and the exchange of sulfate in and out of the cell.

Numerical modeling of benthic processes in the deep Arabian Sea

NASA Astrophysics Data System (ADS)

Luff, Roger; Wallmann, Klaus; Grandel, Sibylle; Schlüter, Michael

Aerobic and anaerobic degradation of particulate organic carbon (POC) and carbonate equilibria in deep-sea surface sediments were studied at five stations located in the western (WAST), northern (NAST), eastern (EAST), central (CAST), and southern (SAST) Arabian Sea. In situ oxygen fluxes, porewater profiles of dissolved oxygen, nitrate, and Mn, pH profiles and solid-phase profiles of particulate organic carbon, Mn, and Fe were measured at each station. An early diagenesis model was applied to simulate the degradation and dissolution processes and to determine the benthic fluxes of POC, oxygen, nitrate, phosphate, CO 2, HCO 3-, and CO 32-. The benthic data sets were evaluated to constrain the POC input and the kinetics of organic matter degradation used in the model. The modeling showed that the POC rain rate to the seafloor is high at the western and northern stations, and decreases towards the southeast. At stations located in the vicinity of continental margins (WAST, NAST, EAST), 5-7% of the primary production sinks to the deep-sea floor. This unusually high POC rain is either caused by dust particles that accelerate and amplify the particle export from the euphotic zone or by rapid lateral transport processes. At the more remote stations (CAST, SAST) that receive lower dust inputs, the rain efficiency decreases to 1-4%. In the model, organic matter was separated into three fractions (3-G-model) that differ considerably in reactivity. At stations WAST, NAST, EAST, and CAST the bulk of organic matter is composed of extremely labile organic matter with a first order degradation constant ( k) of 15-30 yr -1. The moderately labile fraction with a kinetic constant of 0.2-0.6 yr -1 dominates the POC input at the oligotrophic station in the southern Arabian Sea (SAST). The third fraction that has a very low reactivity ( k=2-5×10 -4 yr -1) is only a minor component of the POC rain at all investigated stations. More than 95% of the organic matter is consumed in aerobic degradation processes. Denitrification and metal oxide reduction only contribute 1-2% to the total POC degradation. At the western station (WAST) a non-negligible portion (2%) of organic matter is consumed via sulfate reduction. The modeling demonstrates that carbonate dissolution is a major process in the deep Arabian Sea; 52-83% of the carbonate rain to the seafloor is dissolved within the surface sediments. In the western Arabian Sea, the monsoon systems produce a strong seasonality in the primary production. Non-steady-state modeling indicates that the benthic oxygen, nutrient, and inorganic carbon fluxes closely follow the seasonal dynamics in primary and export production. This very close benthic-pelagic coupling is established by the extremely labile organic matter fraction that dominates the POC rain to the seafloor. The metabolically released CO 2 induces a seasonal change in carbonate dissolution and carbonate alkalinity fluxes.

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.

Palm tocotrienol-rich fraction inhibits methionine-induced cystathionine β-synthase in rat liver.

PubMed

Kamisah, Yusof; Norsidah, Ku-Zaifah; Azizi, Ayob; Faizah, Othman; Nonan, Mohd Rizal; Asmadi, Ahmad Yusof

2015-12-01

Oxidative stress plays an important role in cardiovascular diseases. The study investigated the effects of dietary palm tocotrienol-rich fraction on homocysteine metabolism in rats fed a high-methionine diet. Forty-two male Wistar rats were randomly assigned to six groups. Five groups were fed with high-methionine diet (1%) for 10 weeks. Groups 2 to 5 were also given dietary folate (8 mg/kg) and three doses of palm tocotrienol-rich fraction (30, 60 and 150 mg/kg) from week 6 to week 10. The last group was only given basal rat chow. High-methionine diet increased plasma homocysteine after 10 weeks, which was prevented by the supplementations of folate and high-dose palm tocotrienol-rich fraction. Hepatic S-adenosyl methionine (SAM) content was unaffected in all groups but S-adenosyl homocysteine (SAH) content was reduced in the folate group. Folate supplementation increased the SAM/SAH ratio, while in the palm tocotrienol-rich fraction groups, the ratio was lower compared with the folate. Augmented activity of hepatic cystathionine β-synthase and lipid peroxidation content by high-methionine diet was inhibited by palm tocotrienol-rich fraction supplementations (moderate and high doses), but not by folate. The supplemented groups had lower hepatic lipid peroxidation than the high-methionine diet. In conclusion, palm tocotrienol-rich fraction reduced high-methionine-induced hyperhomocysteinaemia possibly by reducing hepatic oxidative stress in high-methionine-fed rats. It may also exert a direct inhibitory effect on hepatic cystathionine β-synthase.

The Relationship between Clinical Presentation and Unusual Sensory Interests in Autism Spectrum Disorders: A Preliminary Investigation

ERIC Educational Resources Information Center

Zachor, Ditza A.; Ben-Itzchak, Esther

2014-01-01

Unusual responses to sensory stimuli have been described in autism spectrum disorder (ASD).The study examined the frequencies of "unusual sensory interests" and "negative sensory responses" and their relation to functioning in a large ASD population (n = 679). Having "unusual sensory interests" was reported in 70.4%…

44 CFR 9.4 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... subject to high velocity waters including but not limited to hurricane wave wash or tsunamis. On a Flood... normally dry land areas from the overflow of inland and/or tidal waters, and/or the unusual and rapid...

44 CFR 9.4 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... subject to high velocity waters including but not limited to hurricane wave wash or tsunamis. On a Flood... normally dry land areas from the overflow of inland and/or tidal waters, and/or the unusual and rapid...

44 CFR 9.4 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... subject to high velocity waters including but not limited to hurricane wave wash or tsunamis. On a Flood... normally dry land areas from the overflow of inland and/or tidal waters, and/or the unusual and rapid...

44 CFR 9.4 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... subject to high velocity waters including but not limited to hurricane wave wash or tsunamis. On a Flood... normally dry land areas from the overflow of inland and/or tidal waters, and/or the unusual and rapid...

Particle size fractionation of high-amylose rice (Goami 2) flour as an oil barrier in a batter-coated fried system

USDA-ARS?s Scientific Manuscript database

The particle size effects of high-amylose rice (Goami 2) flour on quality attributes of frying batters were characterized in terms of physicochemical, rheological, and oil-resisting properties. High-amylose rice flours were fractionated into four fractions (70, 198, 256, and 415 µm) of which morpho...

Xenotime-(Y) formation from zircon dissolution-precipitation and HREE fractionation: an example from a metamorphosed phosphatic sandstone, Espinhaço fold belt (Brazil)

NASA Astrophysics Data System (ADS)

Franz, Gerhard; Morteani, Giulio; Rhede, Dieter

2015-10-01

We present an example where xenotime-(Y) together with metamorphic zircon replaces detrital zircon in a phosphatic sandstone from the Mesoproterozoic Espinhaço fold belt, Brazil, in a dissolution-precipitation reaction: {{zircon}}1 ( {{relict}} ) + {{P-}}{{bearing fluid}} = {{zircon}}2 ( {{metamorphic}} ) + {{xenotime}}. During the Brasiliano orogeny at 634 ± 19 Ma, the rocks experienced amphibolite facies metamorphism at ≥0.6 GPa/ 550 ± 37 °C (Southern Espinhaço) and ≥0.6 GPa/ 570 ± 35 °C (Northern Espinhaço), constrained by Zr-in-rutile and Ti-in-quartz thermometry and the presence of kyanite + muscovite + quartz. Many of the rocks show unusual rare earth element (REE) patterns with a hump at Gd-Tb-Dy and depletion in light REE. Detrital zircons (with relict ages between 1.5 and 3.3 Ga) show varying degrees of replacement as indicated by the presence of xenotime and associated porosity, from almost pristine to complete alteration. Textural evidence indicates local mobility of Zr and REE at the scale of the thin section. Xenotime-(Y) occurs together with other phosphates, mainly augelite, lazulite, and minerals of the svanbergite-crandallite-goyacite-florencite group. Xenotime-(Y) is very heterogeneous and reaches unusually high contents of up to 14 wt% Gd2O3, 13 wt% Dy2O3, and 3 wt% Tb2O3, corresponding to ≤0.36 REE atoms per formula unit due to the exchange Y = REE. The heavy REE patterns of xenotime-(Y) therefore show variable enrichment in individual elements, which explains the characteristic hump at Gd-Tb-Dy in the REE patterns of the whole rock. Although the rocks reached amphibolite facies conditions, textures indicate that formation of xenotime likely occurred during the early stages of diagenesis—metamorphism. Comparison with REE concentrations in xenotime-(Y) from the literature shows that selective REE incorporation into xenotime-(Y) is controlled by interaction with P-bearing hydrous fluids.

On the Influence of North Pacific Sea Surface Temperature on the Arctic Winter Climate

NASA Technical Reports Server (NTRS)

Hurwitz, Margaret M.; Newman, P. A.; Garfinkel, C. I.

2012-01-01

Differences between two ensembles of Goddard Earth Observing System Chemistry-Climate Model simulations isolate the impact of North Pacific sea surface temperatures (SSTs) on the Arctic winter climate. One ensemble of extended winter season forecasts is forced by unusually high SSTs in the North Pacific, while in the second ensemble SSTs in the North Pacific are unusually low. High Low differences are consistent with a weakened Western Pacific atmospheric teleconnection pattern, and in particular, a weakening of the Aleutian low. This relative change in tropospheric circulation inhibits planetary wave propagation into the stratosphere, in turn reducing polar stratospheric temperature in mid- and late winter. The number of winters with sudden stratospheric warmings is approximately tripled in the Low ensemble as compared with the High ensemble. Enhanced North Pacific SSTs, and thus a more stable and persistent Arctic vortex, lead to a relative decrease in lower stratospheric ozone in late winter, affecting the April clear-sky UV index at Northern Hemisphere mid-latitudes.

[Unusually high level of chromosome variability in cultured human peripheral blood lymphocytes].

PubMed

Bochkov, N P; Popova, N A; Katosova, L D; Iakovleva, Iu S; Nazarenko, S A; Vasil'eva, E O; Platonova, V I; Chebotarev, A N

1999-06-01

A cytogenetic examination carried out in the inhabitants of Seversk (Tomsk oblast) and workers of the Siberian chemical industrial complex (a complex of nuclear-chemical and fuel plants), living in the same town, revealed unusually high level of spontaneous chromosomal variability both in control and industrial groups (total irradiation doses 1.8 to 3.7 and 9.3 to 15.7 Gy, respectively). The frequencies of cells with chromosomal aberrations (estimated per 100 cells) in control and industrial groups were 4.69, 6.04, and 6.64, respectively, and the total number of aberrations constituted 6.93, 8.47 and 12.06, respectively. These frequencies were several times higher compared to the summarized literature data on the control levels. The high average aberration level was caused by the elevated proportion of chromatid-type aberrations and paired fragments. The reasons for this are unclear. The levels of radioactive background and chemical air pollution in the town were not increased.

Unusual high B{sub s} for Fe-based amorphous powders produced by a gas-atomization technique

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

Yoshida, K.; Bito, M.; Kageyama, J.

2016-05-15

Fe-based alloy powders with a high Fe content of about 81 at.% were produced by a gas-atomization technique. Powders of Fe{sub 81}Si{sub 1.9}B{sub 5.7}P{sub 11.4} (at.%) alloy showed a good glass forming ability and exhibited unusual high saturation magnetic flux density of 1.57 T. The core-loss property at a frequency of 100 kHz for the compacted core made of the Fe{sub 81}Si{sub 1.9}B{sub 5.7}P{sub 11.4} powder is evaluated to be less than 500 kW/m{sup 3} under a maximum induction of 100 mT. Moreover, good DC-superposition characteristic of the core was also confirmed. These results suggest that the present Fe-based alloymore » powder is promising for low-loss magnetic-core materials and expected to contribute in miniaturization of electric parts in the near future.« less

Unusual multiscale mechanics of biomimetic nanoparticle hydrogels

DOE PAGES

Zhou, Yunlong; Damasceno, Pablo F.; Somashekar, Bagganahalli S.; ...

2018-01-12

Viscoelastic properties are central for gels and other materials. Simultaneously, high storage and loss moduli are difficult to attain due to their contrarian requirements to chemical structure. Biomimetic inorganic nanoparticles offer a promising toolbox for multiscale engineering of gel mechanics, but a conceptual framework for their molecular, nanoscale, mesoscale, and microscale engineering as viscoelastic materials is absent. Here we show nanoparticle gels with simultaneously high storage and loss moduli from CdTe nanoparticles. Viscoelastic figure of merit reaches 1.83 MPa exceeding that of comparable gels by 100–1000 times for glutathione-stabilized nanoparticles. The gels made from the smallest nanoparticles display the highestmore » stiffness, which was attributed to the drastic change of GSH configurations when nanoparticles decrease in size. A computational model accounting for the difference in nanoparticle interactions for variable GSH configurations describes the unusual trends of nanoparticle gel viscoelasticity. These observations are generalizable to other NP gels interconnected by supramolecular interactions and lead to materials with high-load bearing abilities and energy dissipation needed for multiple technologies.« less

Deep melting reveals liquid structural memory and anomalous ferromagnetism in bismuth.

PubMed

Shu, Yu; Yu, Dongli; Hu, Wentao; Wang, Yanbin; Shen, Guoyin; Kono, Yoshio; Xu, Bo; He, Julong; Liu, Zhongyuan; Tian, Yongjun

2017-03-28

As an archetypal semimetal with complex and anisotropic Fermi surface and unusual electric properties (e.g., high electrical resistance, large magnetoresistance, and giant Hall effect), bismuth (Bi) has played a critical role in metal physics. In general, Bi displays diamagnetism with a high volumetric susceptibility ([Formula: see text]10 -4 ). Here, we report unusual ferromagnetism in bulk Bi samples recovered from a molten state at pressures of 1.4-2.5 GPa and temperatures above [Formula: see text]1,250 K. The ferromagnetism is associated with a surprising structural memory effect in the molten state. On heating, low-temperature Bi liquid (L) transforms to a more randomly disordered high-temperature liquid (L') around 1,250 K. By cooling from above 1,250 K, certain structural characteristics of liquid L' are preserved in L. Bi clusters with characteristics of the liquid L' motifs are further preserved through solidification into the Bi-II phase across the pressure-independent melting curve, which may be responsible for the observed ferromagnetism.

Unusual multiscale mechanics of biomimetic nanoparticle hydrogels

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

Zhou, Yunlong; Damasceno, Pablo F.; Somashekar, Bagganahalli S.

Viscoelastic properties are central for gels and other materials. Simultaneously, high storage and loss moduli are difficult to attain due to their contrarian requirements to chemical structure. Biomimetic inorganic nanoparticles offer a promising toolbox for multiscale engineering of gel mechanics, but a conceptual framework for their molecular, nanoscale, mesoscale, and microscale engineering as viscoelastic materials is absent. Here we show nanoparticle gels with simultaneously high storage and loss moduli from CdTe nanoparticles. Viscoelastic figure of merit reaches 1.83 MPa exceeding that of comparable gels by 100–1000 times for glutathione-stabilized nanoparticles. The gels made from the smallest nanoparticles display the highestmore » stiffness, which was attributed to the drastic change of GSH configurations when nanoparticles decrease in size. A computational model accounting for the difference in nanoparticle interactions for variable GSH configurations describes the unusual trends of nanoparticle gel viscoelasticity. These observations are generalizable to other NP gels interconnected by supramolecular interactions and lead to materials with high-load bearing abilities and energy dissipation needed for multiple technologies.« less

Formation of the world's largest REE deposit through protracted fluxing of carbonatite by subduction-derived fluids

PubMed Central

Ling, Ming-Xing; Liu, Yu-Long; Williams, Ian S.; Teng, Fang-Zhen; Yang, Xiao-Yong; Ding, Xing; Wei, Gang-Jian; Xie, Lu-Hua; Deng, Wen-Feng; Sun, Wei-Dong

2013-01-01

Rare Earth Elements (REE) are essential to modern society but the origins of many large REE deposits remain unclear. The U-Th-Pb ages, chemical compositions and C, O and Mg isotopic compositions of Bayan Obo, the world's largest REE deposit, indicate a protracted mineralisation history with unusual chemical and isotopic features. Coexisting calcite and dolomite are in O isotope disequilibrium; some calcitic carbonatite samples show highly varied δ26Mg which increases with increasing Si and Mg; and ankerite crystals show decreases in Fe and REE from rim to centre, with highly varied REE patterns. These and many other observations are consistent with an unusual mineralisation process not previously considered; protracted fluxing of calcitic carbonatite by subduction-released high-Si fluids during the closure of the Palaeo-Asian Ocean. The fluids leached Fe and Mg from the mantle wedge and scavenged REE, Nb and Th from carbonatite, forming the deposit through metasomatism of overlying sedimentary carbonate.

Deep melting reveals liquid structural memory and anomalous ferromagnetism in bismuth

PubMed Central

Shu, Yu; Yu, Dongli; Hu, Wentao; Wang, Yanbin; Shen, Guoyin; Kono, Yoshio; Xu, Bo; He, Julong; Liu, Zhongyuan; Tian, Yongjun

2017-01-01

As an archetypal semimetal with complex and anisotropic Fermi surface and unusual electric properties (e.g., high electrical resistance, large magnetoresistance, and giant Hall effect), bismuth (Bi) has played a critical role in metal physics. In general, Bi displays diamagnetism with a high volumetric susceptibility (∼10−4). Here, we report unusual ferromagnetism in bulk Bi samples recovered from a molten state at pressures of 1.4–2.5 GPa and temperatures above ∼1,250 K. The ferromagnetism is associated with a surprising structural memory effect in the molten state. On heating, low-temperature Bi liquid (L) transforms to a more randomly disordered high-temperature liquid (L′) around 1,250 K. By cooling from above 1,250 K, certain structural characteristics of liquid L′ are preserved in L. Bi clusters with characteristics of the liquid L′ motifs are further preserved through solidification into the Bi-II phase across the pressure-independent melting curve, which may be responsible for the observed ferromagnetism. PMID:28289195

Hit to lead account of the discovery of a new class of inhibitors of Pim kinases and crystallographic studies revealing an unusual kinase binding mode.

PubMed

Qian, Kevin; Wang, Lian; Cywin, Charles L; Farmer, Bennett T; Hickey, Eugene; Homon, Carol; Jakes, Scott; Kashem, Mohammed A; Lee, George; Leonard, Scott; Li, Jun; Magboo, Ronald; Mao, Wang; Pack, Edward; Peng, Charlene; Prokopowicz, Anthony; Welzel, Morgan; Wolak, John; Morwick, Tina

2009-04-09

A series of inhibitors of Pim-2 kinase identified by high-throughput screening is described. Details of the hit validation and lead generation process and structure-activity relationship (SAR) studies are presented. Disclosure of an unconventional binding mode for 1, as revealed by X-ray crystallography using the highly homologous Pim-1 protein, is also presented, and observed binding features are shown to correlate with the Pim-2 SAR. While highly selective within the kinase family, the series shows similar potency for both Pim-1 and Pim-2, which was expected on the basis of homology, but unusual in light of reports in the literature documenting a bias for Pim-1. A rationale for these observations based on Pim-1 and Pim-2 K(M(ATP)) values is suggested. Some interesting cross reactivity with casein kinase-2 was also identified, and structural features which may contribute to the association are discussed.

Difference in distribution of membrane proteins between low- and high-density secretory granules in parotid acinar cells

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

Fujita-Yoshigaki, Junko; Katsumata, Osamu; Matsuki, Miwako

Secretory granules (SGs) are considered to be generated as immature granules and to mature by condensation of their contents. In this study, SGs of parotid gland were separated into low-, medium-, and high-density granule fractions by Percoll-density gradient centrifugation, since it was proposed that the density corresponds to the degree of maturation. The observation with electron microscopy showed that granules in the three fractions were very similar. The average diameter of high-density granules was a little but significantly larger than that of low-density granules. Although the three fractions contained amylase, suggesting that they are all SGs, distribution of membrane proteinsmore » was markedly different. Syntaxin6 and VAMP4 were localized in the low-density granule fraction, while VAMP2 was concentrated in the high-density granule fraction. Immunoprecipitation with anti-syntaxin6 antibody caused coprecipitation of VAMP2 from the medium-density granule fraction without solubilization, but not from Triton X-100-solubilized fraction, while VAMP4 was coprecipitated from both fractions. Therefore, VAMP2 is present on the same granules, but is separated from syntaxin6 and VAMP4, which are expected to be removed from immature granules. These results suggest that the medium-density granules are intermediates from low- to high-density granules, and that the membrane components of SGs dynamically change by budding and fusion during maturation.« less

Latino Migrant Parent Influence on Latino Migrant Student University Enrollment

ERIC Educational Resources Information Center

Gonzalez, Alejandro

2013-01-01

Migrant families have long been victims of their unusual lifestyle. High poverty conditions combined with constant mobility in search for agricultural work have contributed to their challenging lifestyle. As a result, Latino migrant students are among the least likely to graduate from high school and pursue a college degree. However, in spite of…

"Helicobacter Pylori" Infection in Five Inpatient Units for People with Intellectual Disability and Psychiatric Disorder

ERIC Educational Resources Information Center

Clarke, David; Vemuri, Murali; Gunatilake, Deepthi; Tewari, Sidhartha

2008-01-01

Background: A high prevalence of "Helicobacter pylori" infection has been reported among people with intellectual disability, especially those residing in hospital and similar settings. Surveys of inpatients have found unusually high rates of gastrointestinal malignancy, to which "H. pylori" infection predisposes. Methods: "Helicobacter pylori"…

High Prevalence of Obesity in Ambulatory Children and Adolescents with Intellectual Disability

ERIC Educational Resources Information Center

Stewart, L.; Van de Ven, L.; Katsarou, V.; Rentziou, E.; Doran, M.; Jackson, P.; Reilly, J. J.; Wilson, D.

2009-01-01

Background: Obesity prevalence is unusually high among adults with intellectual disability (ID). There is limited and conflicting evidence on obesity prevalence among ambulatory children and adolescents with ID. The present study aimed to estimate obesity prevalence in this group and to compare with population prevalence. Methods: Survey of nine…

The Biosynthesis of Nitrogen-, Sulfur-, and High-carbon Chain-containing Sugars†

PubMed Central

Lin, Chia-I; McCarty, Reid M.; Liu, Hung-wen

2013-01-01

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. PMID:23348524

(MnH9)2- salts with high hydrogen contents and unusual bonding: Density functional calculations

NASA Astrophysics Data System (ADS)

Gupta, Michèle; Gupta, Raju P.; Singh, D. J.

2009-12-01

The compounds BaReH9 and K2ReH9 are the prototypical members of a family of hydrides described as salts of (ReH9)2- anions. The structures reflect highly unusual chemistry with short H-H distances and at the same time very high ninefold coordination of Re by hydrogen atoms. This is of interest because of the resulting high hydrogen-to-metal ratios, 4.5 in BaReH9 and 3 in K2ReH9 . Here we use density functional calculations to investigate possible new members of this family including both Re and Mn compounds. We find that although SrReH9 and CaReH9 have not been synthesized these are very likely to be stable compounds that may be prepared in a similar manner as the Ba analog. We also find that the manganese counterparts, including K2MnH9 , are also likely to be stable and have thermodynamic properties consistent with requirements for hydrogen storage.

Unusual regioversatility of acetyltransferase Eis, a cause of drug resistance in XDR-TB

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

Chen, Wenjing; Biswas, Tapan; Porter, Vanessa R.

2011-09-06

The emergence of multidrug-resistant and extensively drug-resistant (XDR) tuberculosis (TB) is a serious global threat. Aminoglycoside antibiotics are used as a last resort to treat XDR-TB. Resistance to the aminoglycoside kanamycin is a hallmark of XDR-TB. Here, we reveal the function and structure of the mycobacterial protein Eis responsible for resistance to kanamycin in a significant fraction of kanamycin-resistant Mycobacterium tuberculosis clinical isolates. We demonstrate that Eis has an unprecedented ability to acetylate multiple amines of many aminoglycosides. Structural and mutagenesis studies of Eis indicate that its acetylation mechanism is enabled by a complex tripartite fold that includes two generalmore » control non-derepressible 5 (GCN5)-related N-acetyltransferase regions. An intricate negatively charged substrate-binding pocket of Eis is a potential target of new antitubercular drugs expected to overcome aminoglycoside resistance.« less

Analysis of the flavonoid component of bioactive New Zealand mānuka (Leptospermum scoparium) honey and the isolation, characterisation and synthesis of an unusual pyrrole.

PubMed

Chan, Ching W; Deadman, Benjamin J; Manley-Harris, Merilyn; Wilkins, Alistair L; Alber, Dagmar G; Harry, Elizabeth

2013-12-01

The flavonoid components of New Zealand mānuka (Leptospermum scoparium) honey have been quantified in a series of 31 honeys of varying non-peroxide antibacterial activity to clarify discrepancies between previous studies reported in the literature. Total flavonoid content was 1.16 mg/100 g honey. The principal flavonoids present were pinobanksin, pinocembrin, luteolin and chrysin and together these represented 61% of the total flavonoid content. 1, 2-formyl-5-(2-methoxyphenyl)-pyrrole, which was weakly correlated with the non-peroxide antibacterial activity, was isolated from the flavonoid fraction and separately synthesised. 1 did not display inhibitory activity against Staphylococcus aureus in vitro and thus the origin of the correlation, which is still unknown, is not a direct contribution. Copyright © 2013 Elsevier Ltd. All rights reserved.

Anomalous Brownian motion discloses viscoelasticity in the ear's mechanoelectrical-transduction apparatus.

PubMed

Kozlov, Andrei S; Andor-Ardó, Daniel; Hudspeth, A J

2012-02-21

The ear detects sounds so faint that they produce only atomic-scale displacements in the mechanoelectrical transducer, yet thermal noise causes fluctuations larger by an order of magnitude. Explaining how hearing can operate when the magnitude of the noise greatly exceeds that of the signal requires an understanding both of the transducer's micromechanics and of the associated noise. Using microrheology, we characterize the statistics of this noise; exploiting the fluctuation-dissipation theorem, we determine the associated micromechanics. The statistics reveal unusual Brownian motion in which the mean square displacement increases as a fractional power of time, indicating that the mechanisms governing energy dissipation are related to those of energy storage. This anomalous scaling contradicts the canonical model of mechanoelectrical transduction, but the results can be explained if the micromechanics incorporates viscoelasticity, a salient characteristic of biopolymers. We amend the canonical model and demonstrate several consequences of viscoelasticity for sensory coding.

Anomalous Brownian motion discloses viscoelasticity in the ear’s mechanoelectrical-transduction apparatus

PubMed Central

Kozlov, Andrei S.; Andor-Ardó, Daniel; Hudspeth, A. J.

2012-01-01

The ear detects sounds so faint that they produce only atomic-scale displacements in the mechanoelectrical transducer, yet thermal noise causes fluctuations larger by an order of magnitude. Explaining how hearing can operate when the magnitude of the noise greatly exceeds that of the signal requires an understanding both of the transducer’s micromechanics and of the associated noise. Using microrheology, we characterize the statistics of this noise; exploiting the fluctuation-dissipation theorem, we determine the associated micromechanics. The statistics reveal unusual Brownian motion in which the mean square displacement increases as a fractional power of time, indicating that the mechanisms governing energy dissipation are related to those of energy storage. This anomalous scaling contradicts the canonical model of mechanoelectrical transduction, but the results can be explained if the micromechanics incorporates viscoelasticity, a salient characteristic of biopolymers. We amend the canonical model and demonstrate several consequences of viscoelasticity for sensory coding. PMID:22328158

Scanning Tunneling Microscopy Observation of Phonon Condensate

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

Altfeder, Igor; Balatsky, Alexander V.; Voevodin, Andrey A.

Using quantum tunneling of electrons into vibrating surface atoms, phonon oscillations can be observed on the atomic scale. Phonon interference patterns with unusually large signal amplitudes have been revealed by scanning tunneling microscopy in intercalated van der Waals heterostructures. Our results show that the effective radius of these phonon quasi-bound states, the real-space distribution of phonon standing wave amplitudes, the scattering phase shifts, and the nonlinear intermode coupling strongly depend on the presence of defect-induced scattering resonance. The observed coherence of these quasi-bound states most likely arises from phase- and frequency-synchronized dynamics of all phonon modes, and indicates the formationmore » of many-body condensate of optical phonons around resonant defects. We found that increasing the strength of the scattering resonance causes the increase of the condensate droplet radius without affecting the condensate fraction inside it. The condensate can be observed at room temperature.« less

Scanning Tunneling Microscopy Observation of Phonon Condensate

PubMed Central

Altfeder, Igor; Voevodin, Andrey A.; Check, Michael H.; Eichfeld, Sarah M.; Robinson, Joshua A.; Balatsky, Alexander V.

2017-01-01

Using quantum tunneling of electrons into vibrating surface atoms, phonon oscillations can be observed on the atomic scale. Phonon interference patterns with unusually large signal amplitudes have been revealed by scanning tunneling microscopy in intercalated van der Waals heterostructures. Our results show that the effective radius of these phonon quasi-bound states, the real-space distribution of phonon standing wave amplitudes, the scattering phase shifts, and the nonlinear intermode coupling strongly depend on the presence of defect-induced scattering resonance. The observed coherence of these quasi-bound states most likely arises from phase- and frequency-synchronized dynamics of all phonon modes, and indicates the formation of many-body condensate of optical phonons around resonant defects. We found that increasing the strength of the scattering resonance causes the increase of the condensate droplet radius without affecting the condensate fraction inside it. The condensate can be observed at room temperature. PMID:28225066

Scanning Tunneling Microscopy Observation of Phonon Condensate

DOE PAGES

Altfeder, Igor; Balatsky, Alexander V.; Voevodin, Andrey A.; ...

2017-02-22

Using quantum tunneling of electrons into vibrating surface atoms, phonon oscillations can be observed on the atomic scale. Phonon interference patterns with unusually large signal amplitudes have been revealed by scanning tunneling microscopy in intercalated van der Waals heterostructures. Our results show that the effective radius of these phonon quasi-bound states, the real-space distribution of phonon standing wave amplitudes, the scattering phase shifts, and the nonlinear intermode coupling strongly depend on the presence of defect-induced scattering resonance. The observed coherence of these quasi-bound states most likely arises from phase- and frequency-synchronized dynamics of all phonon modes, and indicates the formationmore » of many-body condensate of optical phonons around resonant defects. We found that increasing the strength of the scattering resonance causes the increase of the condensate droplet radius without affecting the condensate fraction inside it. The condensate can be observed at room temperature.« less

Symmetry and charge order in Fe2OBO3 studied through polarized resonant x-ray diffraction

NASA Astrophysics Data System (ADS)

Bland, S. R.; Angst, M.; Adiga, S.; Scagnoli, V.; Johnson, R. D.; Herrero-Martín, J.; Hatton, P. D.

2010-09-01

Bond valence sum calculations have previously suggested that iron oxyborate exhibits charge order of the Fe ions with integer 2+/3+ valence states. Meanwhile transition metal oxides typically show much smaller, fractional charge disproportionations. Using resonant x-ray diffraction at the iron K edge, we find resonant features which are much larger than those ordinarily observed in charge ordered oxides. Simulations were subsequently performed using a cluster-based, monoelectronic code. The nanoscale domain structure prevents precise fitting; nevertheless the simulations confirm the diagonal charge order symmetry, as well as the unusually large charge disproportionation. We have demonstrated the conversion of linearly to nonlinearly polarized light and vice versa through full polarization analysis. Simulations show that this effect principally results from interference between the isotropic and anisotropic scattering terms. This mechanism is likely to account for similar observations in alternative systems.

Radar investigation of asteroids

NASA Technical Reports Server (NTRS)

Ostro, S. J.

1983-01-01

For 80 Sappho, 356 Liguria, 694 Ekard, and 2340 Hathor, data were taken simultaneously in the same sense of circular polarization as transmitted (SC) as well as in the opposite (OC) sense. Graphs show the average OC and SC radar echo power spectra soothed to a resolution of EFB Hz and plotted against Doppler frequency. Radar observations of the peculiar object 2201 Oljato reveal an unusual set of echo power spectra. The albedo and polarization ratio remain fairly constant but the bandwidths range from approximately 0.8 Hz to 1.4 Hz and the spectral shapes vary dramatically. Echo characteristics within any one date's approximately 2.5-hr observation period do not fluctuate very much. Laboratory measurements of the radar frequency electrical properties of particulate metal-plus-silicate mixtures can be combined with radar albedo estimates to constrain the bulk density and metal weight, fraction in a hypothetical asteroid regolith having the same particle size distribution as lab samples.

Size distributions and aerodynamic equivalence of metal chondrules and silicate chondrules in Acfer 059

NASA Technical Reports Server (NTRS)

Skinner, William R.; Leenhouts, James M.

1993-01-01

The CR2 chondrite Acfer 059 is unusual in that the original droplet shapes of metal chondrules are well preserved. We determined separate size distributions for metal chondrules and silicate chondrules; the two types are well sorted and have similar size distributions about their respective mean diameters of 0.74 mm and 1.44 mm. These mean values are aerodynamically equivalent for the contrasting densities, as shown by calculated terminal settling velocities in a model solar nebula. Aerodynamic equivalence and similarity of size distributions suggest that metal and silicate fractions experienced the same sorting process before they were accreted onto the parent body. These characteristics, together with depletion of iron in Acfer 059 and essentially all other chondrites relative to primitive CI compositions, strongly suggest that sorting in the solar nebula involved a radial aerodynamic component and that sorting and siderophile depletion in chondrites are closely related.

Time-driven activity-based cost comparison of prostate cancer brachytherapy and intensity-modulated radiation therapy.

PubMed

Dutta, Sunil W; Bauer-Nilsen, Kristine; Sanders, Jason C; Trifiletti, Daniel M; Libby, Bruce; Lash, Donna H; Lain, Melody; Christodoulou, Deborah; Hodge, Constance; Showalter, Timothy N

To evaluate the delivery cost of frequently used radiotherapy options offered to patients with intermediate- to high-risk prostate cancer using time-driven activity-based costing and compare the results with Medicare reimbursement and relative value units (RVUs). Process maps were created to represent each step of prostate radiotherapy treatment at our institution. Salary data, equipment purchase costs, and consumable costs were factored into the cost analysis. The capacity cost rate was determined for each resource and calculated for each treatment option from initial consultation to its completion. Treatment options included low-dose-rate brachytherapy (LDR-BT), combined high-dose-rate brachytherapy single fraction boost with 25-fraction intensity-modulated radiotherapy (HDR-BT-IMRT), moderately hypofractionated 28-fraction IMRT, conventionally fractionated 39-fraction IMRT, and conventionally fractionated (2 Gy/fraction) 23-fraction pelvis irradiation with 16-fraction prostate boost. The total cost to deliver LDR-BT, HDR-BT-IMRT, moderately hypofractionated 28-fraction IMRT, conventionally fractionated 39-fraction IMRT, conventionally fractionated 39-fraction IMRT, and conventionally fractionated (2 Gy/fraction) 23-fraction pelvis irradiation with 16-fraction prostate boost was $2719, $6517, $4173, $5507, and $5663, respectively. Total reimbursement for each course was $3123, $10,156, $7862, $9725, and $10,377, respectively. Radiation oncology attending time was 1.5-2 times higher for treatment courses incorporating BT. Attending radiation oncologist's time consumed per RVU was higher with BT (4.83 and 2.56 minutes per RVU generated for LDR-BT and HDR-BT-IMRT, respectively) compared to without BT (1.41-1.62 minutes per RVU). Time-driven activity-based costing analysis identified higher delivery costs associated with prostate BT compared with IMRT alone. In light of recent guidelines promoting BT for intermediate- to high-risk disease, re-evaluation of payment policies is warranted to encourage BT delivery. Copyright © 2018 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Low Gas Fractions Connect Compact Star-Forming Galaxies to their z~2 Quiescent Descendants

NASA Astrophysics Data System (ADS)

Spilker, Justin; Bezanson, Rachel; Marrone, Daniel P.; Weiner, Benjamin J.; Whitaker, Katherine E.; Williams, Christina C.

2017-01-01

Early quiescent galaxies at z ~ 2 are known to be remarkably compact compared to their nearby counterparts. Possible progenitors of these systems include galaxies that are structurally similar, but are still rapidly forming stars. I will present Karl G. Jansky Very Large Array (VLA) observations of the CO(1-0) line towards three such compact, star-forming galaxies at z ~ 2.3, significantly detecting one. The VLA observations indicate baryonic gas fractions 5 times lower and gas depletion times 10 times shorter than normal, extended massive star-forming galaxies at these redshifts. At their current star formation rates, all three objects will deplete their gas reservoirs within 100Myr. These objects are among the most gas-poor objects observed at z > 2 and are outliers from standard gas scaling relations, a result which remains true regardless of assumptions about the CO-H2 conversion factor. Our observations are consistent with the idea that compact, star-forming galaxies are in a rapid state of transition to quiescence in tandem with the build-up of the z ~ 2 quenched population. In the detected compact galaxy, we see no evidence of rotation or that the CO-emitting gas is spatially extended relative to the stellar light. This casts doubt on recent suggestions that the gas in these compact galaxies is rotating and significantly extended compared to the stars. Instead, we suggest that, at least for this object, the gas is centrally concentrated, and only traces a small fraction of the total galaxy dynamical mass. I will conclude by discussing my ongoing efforts to characterize the gas and star forming properties of this unusual population of galaxies.

Characterization of aerosol particle episodes in Finland caused by wildfires in Eastern Europe

NASA Astrophysics Data System (ADS)

Niemi, J. V.; Tervahattu, H.; Vehkamäki, H.; Martikainen, J.; Laakso, L.; Kulmala, M.; Aarnio, P.; Koskentalo, T.; Sillanpää, M.; Makkonen, U.

2005-08-01

We studied the sources, compositions and size distributions of aerosol particles during long-range transport (LRT) PM2.5 episodes which occurred on 12-15 August, 26-28 August and 5-6 September 2002 in Finland. Backward air mass trajectories, satellite detections of fire areas and dispersion modelling results indicate that emissions from wildfires in Russia and other Eastern European countries arrived in Finland during these episodes. Elemental analyses using scanning electron microscopy (SEM) coupled with energy dispersive X-ray microanalyses (EDX) showed that the proportions of S-rich particles and agglomerates (agglomeration was caused partly by the sampling method used) increased during the episodes, and they contained elevated fractions of K, indicating emissions from biomass burning. These aerosols were mixed with S-rich emissions from fossil fuel burning during transport since air masses came through polluted areas of Europe. Minor amounts of coarse Ca-rich particles were also brought by LRT during the episodes, and they probably originated from wildfires and/or from Estonian and Russian oil-shale-burning industrial areas. Ion chromatography analysis showed that concentrations of sulphate (SO42-), total nitrate (NO3-+HNO3(g)) and total ammonium (NH4++NH3(g)) increased during the episodes, but the ratio of the total amount of these ions to PM10 concentration decreased, indicating unusually high fractions of other chemical components. Particle number size distribution measurements with differential mobility particle sizer (DMPS) revealed that concentrations of particles 90-500 nm increased during the episodes, while concentrations of particles smaller than 90 nm decreased. The reduction of the smallest particles was caused by suppressed new particle formation due to vapour and molecular cluster uptake of LRT particles. Our results show that emissions from wildfires in Russian and other Eastern European countries deteriorated air quality of very large areas, even at distances of over 1000 km from the fire areas.

Characterization of aerosol particle episodes in Finland caused by wildfires in Eastern Europe

NASA Astrophysics Data System (ADS)

Niemi, J. V.; Tervahattu, H.; Vehkamäki, H.; Martikainen, J.; Laakso, L.; Kulmala, M.; Aarnio, P.; Koskentalo, T.; Sillanpää, M.; Makkonen, U.

2005-04-01

We studied the sources, compositions and size distributions of aerosol particles during long-range transport (LRT) PM2.5 episodes occurred on 12-15 August, 26-28 August and 5-6 September 2002 in Finland. Backward air mass trajectories, satellite detections of fire areas, and dispersion modelling results indicate that emissions from wildfires in Russia and other Eastern European countries arrived to Finland during the episodes. Individual particle analyses using scanning electron microscopy (SEM) coupled with energy dispersive X-ray analyses (EDX) showed that the proportion of S-rich particles increased during the episodes and they contained elevated fractions of K, which indicates emissions from biomass burning. These aerosols were mixed with S-rich emissions from fossil fuel burning during the transport, since air masses came through polluted areas of Europe. Minor amounts of coarse Ca-rich particles were also brought by LRT during the episodes, and they probably originated from wildfires and/or from Estonian and Russian oil-shale burning industrial areas. The ion chromatography analysis showed that concentrations of sulphate (SO42-), total nitrate (NO3-+HNO3(g)) and total ammonium (NH4++NH3(g)) increased during the episodes, but the ratio of total amount of these ions to PM10 concentration decreased indicating unusually high fractions of other chemical components. The particle number size distribution measurements with differential mobility particle sizer (DMPS) showed that the concentrations of 90-500 nm particles increased during the episodes, but the concentrations of particles smaller than 90nm decreased. The reduction of the smallest particles was caused by suppressed new particle formation due to the vapour and molecular cluster uptake of LRT particles. Our results show that the emissions from wildfires in Russian and other Eastern European deteriorated air quality on very large areas, even at the distance of over 1000 km from the fire areas.

Cadmium and zinc isotopes of organic-rich marine sediments during Oceanic Anoxic Event 2

NASA Astrophysics Data System (ADS)

Sweere, T.; Dickson, A. J.; Jenkyns, H. C.; Porcelli, D.; Henderson, G. M.; van den Boorn, S.

2017-12-01

Mesozoic Oceanic Anoxic Events (OAEs) are characterized by widespread deposition of organic-rich sediments and the spread of low-oxygen marine environments. To drive and sustain unusually efficient carbon-burial during these events requires high export productivity rates, which has to be supported by an abundance of nutrients in the surface ocean. The presence of redox-sensitive bio-essential micronutrients may be particularly important, and potentially bio-limiting, during such events as they may be drawn down into sediment under low-oxygen conditions. Cadmium and zinc isotopes have potential as tracers for past (micro)nutrient dynamics considering their nutrient-like distribution in the modern ocean and isotope fractionation with uptake by primary producers. The modern deep ocean is generally well mixed for Cd and Zn while short-term cycling of these elements in the surface ocean imposes regional variation. Additional regional variation may be caused by sulfide formation and associated isotope fractionation in euxinic environments. The impact of such regional environmental conditions on the Cd- and Zn-isotope composition of the sediment therefore needs to be addressed in order to explore the use of these elements as a proxy for past nutrient conditions. Here we present an extensive dataset of cadmium- and zinc-isotope compositions of organic-rich marine sediments from different basins deposited during OAE 2 (Late Cretaceous). This comparison highlights regional differences in Cd- and Zn-isotope compositions. However, despite regional environmental controls, a correlation between δ114Cd and δ66Zn across the different sites is observed, which implies a largely similar control on the two isotope systems. When regional environmental controls are accounted for, the data may provide insight in the δ66Zn and δ114Cd evolution of global seawater during OAE 2 as well as information on the global cycling of redox-sensitive micronutrients during the event

Artisanal alcohol production in Mayan Guatemala: chemical safety evaluation with special regard to acetaldehyde contamination.

PubMed

Kanteres, Fotis; Rehm, Jürgen; Lachenmeier, Dirk W

2009-11-01

There is a lack of knowledge regarding the composition, production, distribution, and consumption of artisanal alcohol, particularly in the developing world. In Nahualá, an indigenous Mayan municipality located in highland Guatemala, heavy alcohol consumption appears to have had a significant negative impact on health, a major role in cases of violence and domestic abuse, and a link to street habitation. Cuxa, an artisanally, as well as commercially produced sugarcane alcohol, is widely consumed by heavy drinkers in this community. Cuxa samples from all distribution points in the community were obtained and chemically analyzed for health-relevant constituents and contaminants including methanol, acetaldehyde, higher alcohols, and metals. From those, only acetaldehyde was confirmed to be present in unusually high levels (up to 126 g/hl of pure alcohol), particularly in samples that were produced clandestinely. Acetaldehyde has been evaluated as "possibly carcinogenic" and has also been identified as having significant human exposure in a recent risk assessment. This study explores the reasons for the elevated levels of acetaldehyde, through both sampling and analyses of raw and intermediary products of cuxa production, as well as interviews from producers of the clandestine alcohol. For further insight, we experimentally produced this alcohol in our laboratory, based on the directions provided by the producers, as well as materials from the town itself. Based on these data, the origin of the acetaldehyde contamination appears to be due to chemical changes induced during processing, with the major causative factors consisting of poor hygiene, aerobic working conditions, and inadequate yeast strains, compounded by flawed distillation methodology that neglects separation of the first fractions of the distillate. These results indicate a preventable public health concern for consumers, which can be overcome through education about good manufacturing practices, as well as financial incentives to separate the acetaldehyde-rich fractions during distillation.

Effects of high-pressure extruding pretreatment on MSW upgrading and hydrolysis enhancement.

PubMed

Xu, Shuang; Kong, Xin; Liu, Jianguo; Zhao, Ke; Zhao, Guangqi; Bahdolla, Amanjol

2016-12-01

High-pressure extruding (HPE) is an efficient technology used to separate municipal solid waste (MSW) into wet (biodegradable) and dry (combustible) fractions. Effects of pressure, 10, 20, 30, and 40MPa on quality upgrading of the MSW and hydrolysis of the wet fraction were examined. TS of the dry fraction increased from 48.5% to 59.4% when the extruding pressure increased from 10 to 40MPa, meanwhile the biochemical methane potential (BMP) of the wet fraction extruded under 40MPa was 674mL CH 4 /g·VS, 33% higher than that of the organic fraction of the MSW (OFMSW) control. Furthermore, in the initial stage of hydrolysis experiment, the extruded wet fractions had lower pH and higher COD, volatile fatty acids (VFAs) and COD/VFA than those of the OFMSW control. The results confirmed that HPE upgraded the MSW and enhanced hydrolysis of the wet fractions. However, high extruding pressure as 40MPa aggravated the excessive acidification of the wet fractions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fractionation of persistent organic pollutants in fish oil by high-performance liquid chromatography on a 2-(1-pyrenyl)ethyl silica column.

PubMed

Ortiz, X; Martí, R; Montaña, M J; Gasser, M; Margarit, L; Broto, F; Díaz-Ferrero, J

2010-09-01

The analysis of persistent organic pollutants in foodstuffs has become necessary for control of their levels in products for human and animal consumption. These analytical procedures usually require a fractionation step in order to separate the different families of pollutants to avoid interferences during the instrumental determination. In this study the separation was carried out on a 2-(1-pyrenyl)ethyl silica column, where analyte fractionation was based on differences in planarity and aromaticity. The fractionation of several types of persistent organic pollutants found in fish oil samples was studied; the pollutants included polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, polybrominated diphenyl ethers, and some organochlorine pesticides. Fractions were analyzed by high-resolution gas chromatography with electron-capture detection and high-resolution gas chromatography-high resolution mass spectroscopy. Finally, the whole method (including the purification, fractionation, and instrumental determination steps) was validated and successfully applied to the analysis of several samples of fish oil.

Foam fractionation as a tool to study the air-water interface structure-function relationship of wheat gluten hydrolysates.

PubMed

Wouters, Arno G B; Rombouts, Ine; Schoebrechts, Nele; Fierens, Ellen; Brijs, Kristof; Blecker, Christophe; Delcour, Jan A

2017-03-01

Enzymatic hydrolysis of wheat gluten protein improves its solubility and produces hydrolysates with foaming properties which may find applications in food products. First, we here investigated whether foam-liquid fractionation can concentrate wheat gluten peptides with foaming properties. Foam and liquid fractions had high and very low foam stability (FS), respectively. In addition, foam fractions were able to decrease surface tension more pronouncedly than un-fractionated samples and liquid fractions, suggesting they are able to arrange themselves more efficiently at an interface. As a second objective, foam fractionation served as a tool to study the structural properties of the peptides, causing these differences in air-water interfacial behavior. Zeta potential and surface hydrophobicity measurements did not fully explain these differences but suggested that hydrophobic interactions at the air-water interface are more important than electrostatic interactions. RP-HPLC showed a large overlap between foam and liquid fractions. However, a small fraction of very hydrophobic peptides with relatively high average molecular mass was clearly enriched in the foam fraction. These peptides were also more concentrated in un-fractionated DH 2 hydrolysates, which had high FS, than in DH 6 hydrolysates, which had low FS. These peptides most likely play a key role in stabilizing the air-water interface. Copyright © 2016 Elsevier B.V. All rights reserved.

Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33 secreted from impaired vessels in the skin compared to fractionated irradiation

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

Lee, Eun-Jung, E-mail: forejs2@yuhs.ac; Kim, Jun Won, E-mail: JUNWON@yuhs.ac; Yoo, Hyun, E-mail: gochunghee@yuhs.ac

We have revealed in a porcine skin injury model that eosinophil recruitment was dose-dependently enhanced by a single high-dose irradiation. In this study, we investigated the underlying mechanism of eosinophil-associated skin fibrosis and the effect of high-dose-per-fraction radiation. The dorsal skin of a mini-pig was divided into two sections containing 4-cm{sup 2} fields that were irradiated with 30 Gy in a single fraction or 5 fractions and biopsied regularly over 14 weeks. Eosinophil-related Th2 cytokines such as interleukin (IL)-4, IL-5, and C–C motif chemokine-11 (CCL11/eotaxin) were evaluated by quantitative real-time PCR. RNA-sequencing using 30 Gy-irradiated mouse skin and functional assays in amore » co-culture system of THP-1 and irradiated-human umbilical vein endothelial cells (HUVECs) were performed to investigate the mechanism of eosinophil-mediated radiation fibrosis. Single high-dose-per-fraction irradiation caused pronounced eosinophil accumulation, increased profibrotic factors collagen and transforming growth factor-β, enhanced production of eosinophil-related cytokines including IL-4, IL-5, CCL11, IL-13, and IL-33, and reduced vessels compared with 5-fraction irradiation. IL-33 notably increased in pig and mouse skin vessels after single high-dose irradiation of 30 Gy, as well as in irradiated HUVECs following 12 Gy. Blocking IL-33 suppressed the migration ability of THP-1 cells and cytokine secretion in a co-culture system of THP-1 cells and irradiated HUVECs. Hence, high-dose-per-fraction irradiation appears to enhance eosinophil-mediated fibrotic responses, and IL-33 may be a key molecule operating in eosinophil-mediated fibrosis in high-dose-per fraction irradiated skin. - Highlights: • Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33. • Vascular endothelial cells damaged by high-dose radiation secrete IL-33. • Blocking IL-33 suppressed migration of inflammatory cells and cytokine secretion. • IL-33 is a key in eosinophil-mediated fibrosis in high-dose-per-fraction radiation.« less

Genetics Home Reference: D-bifunctional protein deficiency

MedlinePlus

... between the nose and mouth (philtrum), and a high arch of the hard palate at the roof of the mouth. Affected infants may also have an unusually large space between the bones of the skull (fontanelle). An ...

Gas-separation process

DOEpatents

Toy, L.G.; Pinnau, I.; Baker, R.W.

1994-01-25

A process is described 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. 6 figures.

Biological Studies in Art

ERIC Educational Resources Information Center

Karan, Theodora

1978-01-01

The Biological Studies in Art program offers students at the high school level an unusual opportunity to prepare for a career in biological illustration. This field offers opportunities for employment in museums, publishing houses, and other similar settings. (Author/BB)

High Field Remagnetization of Hematite Concretions from Utah, USA and Czech Republic

NASA Astrophysics Data System (ADS)

Adachi, T.; Kletetschka, G.; Chan, M.; Mikula, V.; Adamovic, J.; Pruner, P.; Schnabl, P.; Wasilewski, P.

2007-03-01

Terrestrial hematite concretions of the Navajo Sandstone have been discussed as analogues to the blueberries on Mars. Magnetic investigation of terrestrial concretions showed unusual behavior of antiferromagnetic hematite-goethite composition that may mem

Prostate Cancer Screening: MedlinePlus Health Topic

MedlinePlus

... unusual. Another test is the prostate-specific antigen (PSA) blood test. Your PSA level may be high if you have prostate ... Research) Prostate Cancer Screening: Should You Get a PSA Test? (Mayo Foundation for Medical Education and Research) ...

A Two-Way Spinoff.

ERIC Educational Resources Information Center

Aviation/Space, 1982

1982-01-01

A unusual technology transfer, involving sailboats and commercial wind energy systems, highlights space-related spinoffs for home, consumer, and recreational use. These include clothing for cooling athletes, high-intensity lighting, an advanced welding tool, and a water filter. (Author/JN)

Spreading like wildfire

NASA Astrophysics Data System (ADS)

2017-11-01

The 2017 wildfire season has seen unusually high fire levels in many parts of the world, with extensive and severe fires occurring in Chile, the Mediterranean, Russia, the US, Canada and even Greenland. Is this a sign of things to come?

MAMMALIAN DNA IN PCR REAGENTS

EPA Science Inventory

Ancient DNA analysis is becoming widespread. These studies use polymerase chain reaction (PCR) to amplify minute quantities of heavily damaged template. Unusual steps are taken to achieve the sensitivity necessary to detect ancient DNA, including high- cycle PCR amplification t...

Dying Star Creates Fantasy-like Sculpture of Gas and Dust

NASA Image and Video Library

2004-09-09

This detailed view of NGC 6543, the Cat Eye Nebula, from NASA Hubble Space Telescope includes intricate structures, including concentric gas shells, jets of high-speed gas, and unusual shock-induced knots of gas.

Atmospheric Fragmentation of the Canyon Diablo Meteoroid

NASA Technical Reports Server (NTRS)

Pierazzo, E.; Artemieva, N. A.

2005-01-01

About 50 kyr ago the impact of an iron meteoroid excavated Meteor Crater, Arizona, the first terrestrial structure widely recognized as a meteorite impact crater. Recent studies of ballistically dispersed impact melts from Meteor Crater indicate a compositionally unusually heterogeneous impact melt with high SiO2 and exceptionally high (10 to 25% on average) levels of projectile contamination. These are observations that must be explained by any theoretical modeling of the impact event. Simple atmospheric entry models for an iron meteorite similar to Canyon Diablo indicate that the surface impact speed should have been around 12 km/s [Melosh, personal comm.], not the 15-20 km/s generally assumed in previous impact models. This may help explaining the unusual characteristics of the impact melt at Meteor Crater. We present alternative initial estimates of the motion in the atmosphere of an iron projectile similar to Canyon Diablo, to constraint the initial conditions of the impact event that generated Meteor Crater.

Detection of the supercycle in V4140 Sagittarii: First eclipsing ER Ursae Majoris-like object

NASA Astrophysics Data System (ADS)

Kato, Taichi; Hambsch, Franz-Josef; Cook, Lewis M.

2018-05-01

We observed the deeply eclipsing SU UMa-type dwarf nova V4140 Sgr and established the very short supercycle of 69.7(3) d. There were several short outbursts between superoutbursts. These values, together with the short orbital period (0.06143 d), were similar to, but not as extreme as, those of ER UMa-type dwarf novae. The object is thus the first, long sought, eclipsing ER UMa-like object. This ER UMa-like nature can naturally explain the high (apparent) quiescent viscosity and unusual temperature profile in quiescence, which were claimed observational features against the thermal-tidal instability model. The apparently unusual outburst behavior can be reasonably explained by a combination of this ER UMa-like nature and the high orbital inclination, and there is no need to introduce mass transfer bursts from its donor star.

Detection of the supercycle in V4140 Sagittarii: First eclipsing ER Ursae Majoris-like object

NASA Astrophysics Data System (ADS)

Kato, Taichi; Hambsch, Franz-Josef; Cook, Lewis M.

2018-06-01

We observed the deeply eclipsing SU UMa-type dwarf nova V4140 Sgr and established the very short supercycle of 69.7(3) d. There were several short outbursts between superoutbursts. These values, together with the short orbital period (0.06143 d), were similar to, but not as extreme as, those of ER UMa-type dwarf novae. The object is thus the first, long sought, eclipsing ER UMa-like object. This ER UMa-like nature can naturally explain the high (apparent) quiescent viscosity and unusual temperature profile in quiescence, which were claimed observational features against the thermal-tidal instability model. The apparently unusual outburst behavior can be reasonably explained by a combination of this ER UMa-like nature and the high orbital inclination, and there is no need to introduce mass transfer bursts from its donor star.

Rapid onset aggressive vertebral haemangioma.

PubMed

Cheung, Nicholas K; Doorenbosch, Xenia; Christie, John G

2011-03-01

Vertebral haemangiomas are generally benign asymptomatic vascular tumours seen commonly in the adult population. Presentations in paediatric populations are extremely rare, which can result in rapid onset of neurological symptoms. We present a highly unusual case of an aggressive paediatric vertebral haemangioma causing significant cord compression. A 13-year-old boy presented with only 2 weeks duration of progressive gait disturbance, truncal ataxia and loss of bladder control. Magnetic resonance imaging (MRI) of the spine revealed a large vascular epidural mass extending between T6 and T8 vertebral bodies. Associated displacement and compression of the spinal cord was present. A highly vascular bony lesion was found during surgery. Histopathology identified this tumour to be a vertebral haemangioma. We present an extremely unusual acute presentation of a paediatric vertebral haemangioma. This study highlights the need for early diagnosis, MRI for investigation and urgent surgical management. © Springer-Verlag 2011

On the occurrence and origin of anthropogenic radionuclides found in a fragment of the Chelyabinsk (LL5) meteorite

NASA Astrophysics Data System (ADS)

Querfeld, Rebecca; Tanha, Mohammad R.; Heyer, Lars; Renz, Franz; Guggenberger, Georg; Brandstätter, Franz; Ferrière, Ludovic; Koeberl, Christian; Steinhauser, Georg

2017-06-01

A piece of the 2013 Chelyabinsk meteorite was investigated for its content of anthropogenic radionuclides. In addition to traces of cesium-137 that had been previously reported for this particular fragment, we found an unusually high amount of strontium-90, which indicates that the source of this contamination was the Kyshtym accident (1957). A high Sr-90/Cs-137 activity ratio is characteristic for Kyshtym-derived contaminations. Based on the cesium-137 content in the soil from the finding site, it is estimated that the fragment was contaminated with soil particles in the milligram range upon impact. Investigation of the soil revealed very unusual ferromagnetic characteristics and an iron-rich chemical composition. Mössbauer spectroscopy indicated the presence of steel components in this soil, suggesting that the investigated meteorite fragment was found in an industrial dumping site rather than natural soil.

Properties of an unusual DNA primase from an archaeal plasmid

PubMed Central

Beck, Kirsten; Lipps, Georg

2007-01-01

Primases are specialized DNA-dependent RNA polymerases that synthesize a short oligoribonucleotide complementary to single-stranded template DNA. In the context of cellular DNA replication, primases are indispensable since DNA polymerases are not able to start DNA polymerization de novo. The primase activity of the replication protein from the archaeal plasmid pRN1 synthesizes a rather unusual mixed primer consisting of a single ribonucleotide at the 5′ end followed by seven deoxynucleotides. Ribonucleotides and deoxynucleotides are strictly required at the respective positions within the primer. Furthermore, in contrast to other archaeo-eukaryotic primases, the primase activity is highly sequence-specific and requires the trinucleotide motif GTG in the template. Primer synthesis starts outside of the recognition motif, immediately 5′ to the recognition motif. The fidelity of the primase synthesis is high, as non-complementary bases are not incorporated into the primer. PMID:17709343

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.

A COMPARATIVE STUDY OF KNOTS OF STAR FORMATION IN INTERACTING VERSUS SPIRAL GALAXIES

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

Smith, Beverly J.; Olmsted, Susan; Jones, Keith

2016-03-15

Interacting galaxies are known to have higher global rates of star formation on average than normal galaxies, relative to their stellar masses. Using UV and IR photometry combined with new and published Hα images, we have compared the star formation rates (SFRs) of ∼700 star forming complexes in 46 nearby interacting galaxy pairs with those of regions in 39 normal spiral galaxies. The interacting galaxies have proportionally more regions with high SFRs than the spirals. The most extreme regions in the interacting systems lie at the intersections of spiral/tidal structures, where gas is expected to pile up and trigger starmore » formation. Published Hubble Space Telescope images show unusually large and luminous star clusters in the highest luminosity regions. The SFRs of the clumps correlate with measures of the dust attenuation, consistent with the idea that regions with more interstellar gas have more star formation. For the clumps with the highest SFRs, the apparent dust attenuation is consistent with the Calzetti starburst dust attenuation law. This suggests that the high luminosity regions are dominated by a central group of young stars surrounded by a shell of clumpy interstellar gas. In contrast, the lower luminosity clumps are bright in the UV relative to Hα, suggesting either a high differential attenuation between the ionized gas and the stars, or a post-starburst population bright in the UV but faded in Hα. The fraction of the global light of the galaxies in the clumps is higher on average for the interacting galaxies than for the spirals. Thus either star formation in interacting galaxies is “clumpier” on average, or the star forming regions in interacting galaxies are more luminous, dustier, or younger on average.« less

The Infrared Properties of Sources Matched in the Wise All-Sky and Herschel ATLAS Surveys

NASA Technical Reports Server (NTRS)

Bond, Nicholas A.; Benford, Dominic J.; Gardner, Jonathan P.; Amblard, Alexandre; Fleuren, Simone; Blain, Andrew W.; Dunne, Loretta; Smith, Daniel J. B.; Maddox, Steve J.; Hoyos, Carlos;

The Infrared Properties of Sources Matched in the WISE All-Sky and Herschel Atlas Surveys

NASA Technical Reports Server (NTRS)

Bond, Nicholas A.; Benford, Dominic J.; Gardner, Jonathan P.; Eisenhardt, Peter; Amblard, Alexandre; Temi, Pasquale; Fleuren, Simone; Blain, Andrew W.; Dunne, Loretta; Smith, Daniel J.;

Preferred carbon precursors for lipid labelling in the heterotrophic endosperm of developing oat (Avena sativa L.) grains.

PubMed

Grimberg, Åsa

2014-10-01

Oat (Avena sativa L.) is unusual among the cereal grains in storing high amounts of oil in the endosperm; up to 90% of total grain oil. By using oat as a model species for oil metabolism in the cereal endosperm, we can learn how to develop strategies to redirect carbon from starch to achieve high-oil yielding cereal crops. Carbon precursors for lipid synthesis were compared in two genetically close oat cultivars with different endosperm oil content (about 6% and 10% of grain dw, medium-oil; MO, and high-oil; HO cultivar, respectively) by supplying a variety of (14)C-labelled substrates to the grain from both up- and downstream parts of glycolysis, either through detached oat panicles in vitro or by direct injection in planta. When supplied by direct injection, (14)C from acetate was identified to label the lipid fraction of the grain to the highest extent among substrates tested; 46% of net accumulated (14)C, demonstrating its applicability as a marker for lipids in the endosperm. Time course analyses of injected (14)C acetate during grain development suggested a more efficient transfer of fatty acids from polar lipids to triacylglycerol in the HO as compared to the MO cultivar, and turnover of triacylglycerol was suggested to not play a major role for the final oil content of oat grain endosperm despite the low amount of protective oleosins in this tissue. Moreover, availability of light was shown to drastically affect grain net carbon accumulation from (14)C-sucrose when supplied through detached panicles for the HO cultivar. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

High-shear, jet-cooking, and alkali treatment of corn distillers' dried grains to obtain products with enhanced protein, oil and phenolic antioxidants.

PubMed

Inglett, G E; Chen, D; Rose, D J; Berhow, M

2010-08-01

Distillers dried grains (DDG) have potential to be a nutritionally important source of protein, oil and phenolic antioxidants. DDG was subjected to high-shear and jet-cooking, with or without alkaline pH adjustment and autoclaving. Soluble and insoluble fractions were analyzed for protein, oil and ash. Extracts were analyzed for phenolic acids and antioxidant activity. Protein contents were significantly elevated in the insoluble fractions after treatment and the oil content was drastically increased in the insoluble fraction after high-shear and jet-cooking without pH adjustment. Alkaline pH adjustment resulted in a soluble fraction that was highest in phenolic acids, but not antioxidant activity. The highest antioxidant activity was found in the 50% ethanol extract from DDG that had been subjected to high-shear and jet-cooking. These results suggest that high-shear and jet-cooking may be useful processing treatments to increase the value of DDG by producing fractions high in protein, oil and extractable phenolic acids with high antioxidant activity. The DDG fractions and extracts described herein may be useful as food and nutraceutical ingredients, and, if used for these applications, will increase the value of DDG and ease economic burdens on ethanol producers, allowing them to compete in the bio-fuel marketplace.

Antipsychotic polypharmacy prescribing patterns and costs in the Florida adult and child Medicaid populations.

PubMed

Becker, Edmund R; Constantine, Robert J; McPherson, Marie A; Jones, Mary Elizabeth

2013-01-01

The rapid growth in the use of antipsychotic medications and their related costs have resulted in states developing programs to measure, monitor, and insure their beneficial relevance to public program populations. One such program developed in the state of Florida has adopted an evidence-based approach to identify prescribers with unusual psychotherapeutic prescription patterns and track their utilization and costs among Florida Medicaid patients. This study reports on the prescriber prescription and cost patterns for adults and children using three measures of unusual antipsychotic prescribing patterns: (1) two antipsychotics for 60 days (2AP60), (2) three antipsychotics for 60 days (3AP60), and (2) two antipsychotics for 90 or more days (2AP90). We find that over the four-year study period there were substantial increases in several aspects of the Florida Medicaid behavioral drug program. Overall, for adults and children, patient participation increased by 29 percent, the number of prescriptions grew by 30 percent, and the number of prescribers that wrote at least one prescription grew 48.5 percent, while Medicaid costs for behavioral drugs increased by 32 percent. But the results are highly skewed. We find that a relatively small number of prescribers account for a disproportionately large share of prescriptions and costs of the unusual antipsychotic prescriptions. In general, the top 350 Medicaid prescribers accounted for more than 70 percent of the unusual antipsychotic prescriptions, and we find that this disparity in unusual prescribing patterns appears to be substantially more pronounced in adults than in children prescribers. For just the top 13 adult and children prescribers, their practice patterns accounted for 11 percent to 21 percent of the unusual prescribing activity and, overall, these 13 top prescribers accounted for 13 percent of the total spent on antipsychotics by the Florida Medicaid program and 9.3 percent of the total expenditure by the state for all drugs. Our findings suggest that a strategy to monitor and ensure patient safety and prescribing patterns that targets a relatively small number of Medicaid providers could have a substantial benefit and prove to be cost effective.

Unusually large oilbodies are highly correlated with lower oil content in Brassica napus.

PubMed

Hu, Zhiyong; Wang, Xinfa; Zhan, Gaomiao; Liu, Guihua; Hua, Wei; Wang, Hanzhong

2009-04-01

Rapeseed cultivars exhibit a wide range of oil content in the mature seeds. Little is known about the relationship between the oilbody structures and the differences in oil contents of Brassica napus cultivars. In the present study, the oilbody morphology and its fate during the embryo development and seedling growth in several cultivars with oil contents ranging from 33.4 to 49.8% were studied. Cultivars with low oil contents (LO), some of the oilbodies were in similar size to those in cultivars with high oil content (HO), while some oilbodies in the LO cultivars were several times bigger (over 5.0 microm). These are much larger than the average size of B. napus seed oilbodies that were previously reported (Mantese et al. Ann Bot 97:999-1010, 2006). The oleosin protein levels and oleosin1 gene transcript abundances in the HO cultivars were clearly higher than in the LO cultivars. The shapes of oilbodies were similar during early stages of embryo development in both HO and LO cultivars, while as the embryos matured, the unusually large oilbodies were generated in the LO cells. After germination, the oilbodies in LO cultivars were consumed more slowly than in HO, and the seed germination rates of LO cultivars were less than those of HO cultivars. The low accumulation of oleosins results in the forming of unusually large oilbodies in LO cultivars.

Low or High Fractionation Dose {beta}-Radiotherapy for Pterygium? A Randomized Clinical Trial

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

Viani, Gustavo Arruda, E-mail: gusviani@gmail.com; De Fendi, Ligia Issa; Fonseca, Ellen Carrara

2012-02-01

Purpose: Postoperative adjuvant treatment using {beta}-radiotherapy (RT) is a proven technique for reducing the recurrence of pterygium. A randomized trial was conducted to determine whether a low fractionation dose of 2 Gy within 10 fractions would provide local control similar to that after a high fractionation dose of 5 Gy within 7 fractions for surgically resected pterygium. Methods: A randomized trial was conducted in 200 patients (216 pterygia) between February 2006 and July 2007. Only patients with fresh pterygium resected using a bare sclera method and given RT within 3 days were included. Postoperative RT was delivered using a strontium-90more » eye applicator. The pterygia were randomly treated using either 5 Gy within 7 fractions (Group 1) or 2 Gy within 10 fractions (Group 2). The local control rate was calculated from the date of surgery. Results: Of the 216 pterygia included, 112 were allocated to Group 1 and 104 to Group 2. The 3-year local control rate for Groups 1 and 2 was 93.8% and 92.3%, respectively (p = .616). A statistically significant difference for cosmetic effect (p = .034), photophobia (p = .02), irritation (p = .001), and scleromalacia (p = .017) was noted in favor of Group 2. Conclusions: No better local control rate for postoperative pterygium was obtained using high-dose fractionation vs. low-dose fractionation. However, a low-dose fractionation schedule produced better cosmetic effects and resulted in fewer symptoms than high-dose fractionation. Moreover, pterygia can be safely treated in terms of local recurrence using RT schedules with a biologic effective dose of 24-52.5 Gy{sub 10.}.« less

High-accuracy power series solutions with arbitrarily large radius of convergence for the fractional nonlinear Schrödinger-type equations

NASA Astrophysics Data System (ADS)

Khawaja, U. Al; Al-Refai, M.; Shchedrin, Gavriil; Carr, Lincoln D.

2018-06-01

Fractional nonlinear differential equations present an interplay between two common and important effective descriptions used to simplify high dimensional or more complicated theories: nonlinearity and fractional derivatives. These effective descriptions thus appear commonly in physical and mathematical modeling. We present a new series method providing systematic controlled accuracy for solutions of fractional nonlinear differential equations, including the fractional nonlinear Schrödinger equation and the fractional nonlinear diffusion equation. The method relies on spatially iterative use of power series expansions. Our approach permits an arbitrarily large radius of convergence and thus solves the typical divergence problem endemic to power series approaches. In the specific case of the fractional nonlinear Schrödinger equation we find fractional generalizations of cnoidal waves of Jacobi elliptic functions as well as a fractional bright soliton. For the fractional nonlinear diffusion equation we find the combination of fractional and nonlinear effects results in a more strongly localized solution which nevertheless still exhibits power law tails, albeit at a much lower density.

Fat tissue is not a reservoir for radiocesium in wild boars.

PubMed

Steinhauser, Georg; Knecht, Christian; Sipos, Wolfgang

2017-01-01

Meat of wild boars is not only known for high 137 Cs activity concentrations but also for the remarkable constancy of these levels. Even decades after the Chernobyl accident, the 137 Cs levels in wild boar meat in Central Europe have not declined but even partly increased. In the present study, we investigated an unusual hypothesis for this very unusual phenomenon: may the boars' fat tissue act as a reservoir for radiocesium? We investigated fat and muscle tissues of four wild boars in Western Germany and found that the 137 Cs concentrations in fat were in the range of 10-30% of the respective activities in muscle tissue. Hence, the hypothesis was refuted.

Myxomatosis on the Western Plains of Victoria.

PubMed Central

Tighe, F. G.; Edmonds, J. W.; Nolan, I. F.; Shepherd, R. C.; Gocs, A.

1977-01-01

Myxomatosis on the Western Plains is an enzootic disease in contrast with the epizootic pattern which is general in eastern Australia. The most unusual aspects are the presence of significant numbers of diseased rabbits throughout the winter and the continuously low percentage of rabbits with antibodies to myxoma virus. Climatic and topographic conditions are unsuited to the production of the high densities of mosquitoes necessary for widespread epizootics. Under these conditions the effects of less efficient methods of myxomatosis transmission are apparent. The unusual epidemiology of myxomatosis has resulted in selection for virulence of the virus similar to that which has occurred under summer epizootic conditions. All field strains are now in the mid range of virulence. PMID:20473

Myxomatosis on the Western Plains of Victoria.

PubMed

Tighe, F G; Edmonds, J W; Nolan, I F; Shepherd, R C; Gocs, A

1977-10-01

Myxomatosis on the Western Plains is an enzootic disease in contrast with the epizootic pattern which is general in eastern Australia. The most unusual aspects are the presence of significant numbers of diseased rabbits throughout the winter and the continuously low percentage of rabbits with antibodies to myxoma virus. Climatic and topographic conditions are unsuited to the production of the high densities of mosquitoes necessary for widespread epizootics. Under these conditions the effects of less efficient methods of myxomatosis transmission are apparent. The unusual epidemiology of myxomatosis has resulted in selection for virulence of the virus similar to that which has occurred under summer epizootic conditions. All field strains are now in the mid range of virulence.

Streptococcus anginosus endocarditis and multiple liver abscesses in a splenectomised patient.

PubMed

Finn, Talya; Schattner, Ami; Dubin, Ina; Cohen, Regev

2018-04-27

An unusual case of infective endocarditis and concurrent multiple liver abscesses both caused by Streptococcus anginosus in a splenectomised patient is reported. The microorganism is a very rare cause of endocarditis and its presentation with multiple liver abscesses is highly unusual. It was initially misdiagnosed as Streptococcus sanguinis and issues relating to the different clinical presentations of S. anginosus including the rare cases of endocarditis, the role of the patient's splenectomy and problems that may contribute to its potential laboratory misidentifications are discussed. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

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.

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

Strain accumulation in southern California, 1973-1980.

USGS Publications Warehouse

Savage, J.C.; Prescott, W.H.; Lisowski, M.; King, N.E.

1981-01-01

Frequent surveys of seven trilateration networks in southern California over the interval 1973-1980 suggest that a regional increment in strain may have occurred in 1978-1979. Prior to 1978 and after late 1979 the strain accumulation has been predominantly a uniaxial north-south compression. This secular trend was interrupted sometime in 1978-1979 by an increment in both north-south and east-west extension in five of the seven networks. The onset of this change appears to have occurred first in the networks farthest south. The changes occurred without any unusual seismicity within the networks, but the overall seismicity in southern California was unusually low prior to and has been unusually high since the occurrence. The average principal strain rates for the seven networks in the 1973-1980 interval are 0.17 mu strain/yr north- south contraction and 0.08 mu strain/yr east-west extension. Although the observed increment in strain could be related to unidentified systematic error in the measuring system, a careful review of the measurements and comparisons with three other measuring systems reveal no appreciable cumulative systematic error. -Authors

A pediatric intramedullary spinal cord tumor with unusual solid-cystic and papillary features: a case report.

PubMed

Iwasaki, Takeshi; Kato, Masako; Horie, Yasushi; Kato, Shinsuke; Akatsuka, Keiichi; Watanabe, Takashi; Kuwamoto, Satoshi; Murakami, Ichiro; Hayashi, Kazuhiko

2011-12-01

Spinal cord tumors are rare in children. We report a novel case of pediatric intramedullary spinal cord tumor with unusual solid-cystic and papillary features. Clinically, the patient presented at the age of 3 years with motor deficit and urinary incontinence, and MRI demonstrated multilocular cystic lesions in the thoracic spine. Histologically the tumor consisted of solid, sheet-like components and branching papillary structures, and immunohistochemistry demonstrated positive reactivity for epithelial membrane antigen, cytokeratins (7, AE1/3, CAM5.2), E-cadherin and transthyretin, and negativity for GFAP, S-100 protein, synaptophysin and neurofilament. These histological and immunohistochemical findings appeared to be unique, and were not compatible with the features of classical ependymoma or choroid plexus papilloma. The clinical behavior, characterized by relatively rapid tumor regrowth after surgical resection and a relatively high MIB-1 labeling index, suggest that this tumor might have had moderate malignant potential. This pediatric case appears to be particularly informative with regard to the tumor biology or tumorigenesis of intramedullary spinal cord tumor with unusual solid-cystic and papillary features. © 2011 Japanese Society of Neuropathology.

Pressure Sore at an Unusual Site- the Bilateral Popliteal Fossa: A Case report

PubMed Central

Kataria, Kamal; Sagar, Sushma; Singhal, Manish; Yadav, Rajni

2012-01-01

Pressure sore is tissue ulceration due to unrelieved pressure, altered sensory perception, and exposure to moisture. Geriatric patients with organic problems and patients with spinal cord injuries are the high-risk groups. Soft tissues over bony prominences are the common sites for ulcer development. About 95% of pressure ulcers occur in the lower part of the body. Ischial tuberosity, greater trochanter, sacrum and heel are common sites. In addition to these, pressure sores at unusual sites like nasal alae, malar eminences, cervical region and medial side of knee have also been described. Only 1.6% of the patients present with sores in areas outside the pelvis and lower extremity. In a paraplegic patient, pressure sores are usually over extensor surface of knee and heel but pressure ulcer over popliteal fossa are extremely rare. We herein report a case of a 36-years-old diabetic and paraplegic male, who presented with multiple bed sores involving the sacral area, heels and bilateral popliteal fossa. Popliteal fossa is an unusual site for pressure sores. Only one similar case has been previously reported in the literature. PMID:29181131

Optical Emission Associated with the Galactic Supernova Remnant G179.0+2.6

NASA Astrophysics Data System (ADS)

How, Thomas G.; Fesen, Robert A.; Neustadt, Jack M. M.; Black, Christine S.; Outters, Nicolas

2018-04-01

Narrow passband optical images of the large Galactic supernova remnant G179.0+2.6 reveal a faint but nearly complete emission shell dominated by strong [O 3] 4959,5007 Å line emission. The remnant's optical emission, which consists of both diffuse and filamentary features, is brightest along its southern and northeastern limbs. Deep Hα images detect little coincidence emission indicating an unusually high [O 3]/Hα emission ratio for such a large and apparently old remnant. Low-dispersion optical spectra of several regions confirm large [O 3]/Hα line ratios with typical values around 10. The dominance of [O 3] emission for the majority of the remnant's optical filaments suggests shock velocities above 100 km s-1 are present throughout most of the remnant, likely reflecting a relatively low density ambient ISM. The remnant's unusually strong [O 3] emission adds to the remnant's interesting set of properties which include a thick radio emission shell, radial polarization of its radio emission like that typically seen in young supernova remnants, and an unusually slow-rotating gamma-ray pulsar with a characteristic spin-down age ≃ 50 kyr.

An unusual case of vaginal myiasis

PubMed Central

Jones, Brian L.; Coyne, Michael

2016-01-01

Introduction: Myiasis, a term used to describe the infestation of a live animal by fly larvae, is rarely reported in human subjects. The adult fly lays its eggs on living tissue that progresses to become larvae that feed on living tissue having gone through three developmental stages known as the first, second and third instar. The larvae become pupae before finally developing into adults. Case presentation: We describe an unusual case of a 79-year-old female who collapsed in her garden and lay there for several days before presenting to her local hospital Accident and Emergency department with an infestation of larvae in her vagina labia, identified as those from the Protophormia species northern blowfly. After complete removal of the larvae using tweezers followed by cleansing of the affected area and a course of antibiotics, the patient’s condition improved. A follow-up review by the local gynaecology team revealed no evidence of further infestation. Conclusion: It is our understanding that this is the first highly unusual case of a blowfly larvae infestation to be reported in a human within the UK. PMID:28348792

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.

Biogas production from the mechanically pretreated, liquid fraction of sorted organic municipal solid wastes.

PubMed

Alvarado-Lassman, A; Méndez-Contreras, J M; Martínez-Sibaja, A; Rosas-Mendoza, E S; Vallejo-Cantú, N A

2017-06-01

The high liquid content in fruit and vegetable wastes makes it convenient to mechanically separate these wastes into mostly liquid and solid fractions by means of pretreatment. Then, the liquid fraction can be treated using a high-rate anaerobic biofilm reactor to produce biogas, simultaneously reducing the amount of solids that must be landfilled. In this work, the specific composition of municipal solid waste (MSW) in a public market was determined; then, the sorted organic fraction of municipal solid waste was treated mechanically to separate and characterize the mostly liquid and solid fractions. Then, the mesophilic anaerobic digestion for biogas production of the first fraction was evaluated. The anaerobic digestion resulted in a reduced hydraulic retention time of two days with high removal of chemical oxygen demand, that is, 88% on average, with the additional benefit of reducing the mass of the solids that had to be landfilled by about 80%.

Laboratory simulations of planetary surfaces: Understanding regolith physical properties from remote photopolarimetric observations

NASA Astrophysics Data System (ADS)

Nelson, Robert M.; Boryta, Mark D.; Hapke, Bruce W.; Manatt, Kenneth S.; Shkuratov, Yuriy; Psarev, V.; Vandervoort, Kurt; Kroner, Desire; Nebedum, Adaze; Vides, Christina L.; Quiñones, John

2018-03-01

We present reflectance and polarization phase curve measurements of highly reflective planetary regolith analogues having physical characteristics expected on atmosphereless solar system bodies (ASSBs) such as a eucritic asteroids or icy satellites. We used a goniometric photopolarimeter (GPP) of novel design to study thirteen well-sorted particle size fractions of aluminum oxide (Al2O3). The sample suite included particle sizes larger than, approximately equal to, and smaller than the wavelength of the incident monochromatic radiation (λ = 635 nm). The observed phase angle, α, was 0.056 o < α < 15°. These Al2O3 particulate samples have very high normal reflectance (> ∼95%). The incident radiation has a very high probability of being multiply scattered before being backscattered toward the incident direction or ultimately absorbed. The five smallest particle sizes exhibited extremely high void space (> ∼95%). The reflectance phase curves for all particle size fractions show a pronounced non-linear reflectance increase with decreasing phase angle at α∼ < 3°. Our earlier studies suggest that the cause of this non-linear reflectance increase is constructive interference of counter-propagating waves in the medium by coherent backscattering (CB), a photonic analog of Anderson localization of electrons in solid state media. The polarization phase curves for particle size fractions with size parameter (particle radius/wavelength) r/λ < ∼1, show that the linear polarization rapidly decreases as α increases from 0°; it reaches a minimum near α = ∼2°. Longward of ∼2°, the negative polarization decreases as phase angle increases, becoming positive between 12° and at least 15°, (probably ∼20°) depending on particle size. For size parameters r/λ > ∼1 we detect no polarization. This polarization behavior is distinct from that observed in low albedo solar system objects such as the Moon and asteroids and for absorbing materials in the laboratory. We suggest this behavior arises because photons that are backscattered have a high probability of having interacted with two or more particles, thus giving rise to the CB process. These results may explain the unusual negative polarization behavior observed near small phase angles reported for several decades on highly reflective ASSBs such as the asteroids 44 Nysa, 64 Angelina and the Galilean satellites Io, Europa and Ganymede. Our results suggest these ASSB regoliths scatter electromagnetic radiation as if they were extremely fine grained with void space > ∼95%, and grain sizes of the order < = λ. This portends consequences for efforts to deploy landers on high ASSBs such as Europa. These results are also germane to the field of terrestrial geo-engineering, particularly to suggestions that earth's radiation balance can be modified by injecting Al2O3 particulates into the stratosphere thereby offsetting the effect of anthropogenic greenhouse gas emissions. The GPP used in this study was modified from our previous design so that the sample is presented with light that is alternatingly polarized perpendicular to and parallel to the scattering plane. There are no analyzers before the detector. This optical arrangement, following the Helmholtz Reciprocity Principle (HRP), produces a physically identical result to the traditional laboratory reflectance polarization measurements in which the incident light is unpolarized and the analyzers are placed before the detector. The results are identical in samples measured by both methods. We believe that ours is the first experimental demonstration of the HRP for polarized light, first proposed by Helmholtz in 1856.

Abnormal pelvic morphology and high cervical length are responsible for high-risk pregnancies in women displaying achondroplasia.

PubMed

Vivanti, Alexandre J; Cordier, Anne-Gael; Baujat, Geneviève; Benachi, Alexandra

2016-12-05

Pregnancies of women displaying achondroplasia are at high risk of adverse events. Early sonographic assessment of affected women can indicate an unusually long cervical length. It is the consequence of pathological anatomy of the pelvis. Thus, there is a foreseeable dystocia owing to cephalopelvic disproportion. Furthermore, this situation could also complicate cervical ripening prior to fetal extraction.

ERAST Program Proteus Aircraft in Flight

NASA Image and Video Library

1999-07-26

The unusual design of the Proteus high-altitude aircraft, incorporating a gull-wing shape for its main wing and a long, slender forward canard, is clearly visible in this view of the aircraft in flight over the Mojave Desert in California.

Unusual spacecraft materials

NASA Technical Reports Server (NTRS)

Post, Jonathan V.

1990-01-01

For particularly innovative space exploration missions, unusual requirements are levied on the structural components of the spacecraft. In many cases, the preferred solution is the utilization of unusual materials. This trend is forecast to continue. Several hypothetic examples are discussed.

Event-related potential correlates of paranormal ideation and unusual experiences.

PubMed

Sumich, Alex; Kumari, Veena; Gordon, Evian; Tunstall, Nigel; Brammer, Michael

2008-01-01

Separate dimensions of schizotypy have been differentially associated with electrophysiological measures of brain function, and further shown to be modified by sex/gender. We investigated event-related potential (ERP) correlates of two subdimensions of positive schizotypy, paranormal ideation (PI) and unusual experiences (UEs). Seventy-two individuals with no psychiatric diagnosis (men=36) completed self-report measures of UE and PI and performed an auditory oddball task. Average scores for N100, N200 and P300 amplitudes were calculated for left and right anterior, central and posterior electrode sites. Multiple linear regression was used to examine the relationships between the measures of schizotypy and ERPs across the entire sample, as well as separately according to sex. PI was inversely associated with P300 amplitude at left-central sites across the entire sample, and at right-anterior electrodes in women only. Right-anterior P300 and right-posterior N100 amplitudes were negatively associated with UE in women only. Across the entire sample, UE was negatively associated with left-central N100 amplitude, and positively associated with left-anterior N200 amplitude. These results provide support from electrophysiological measures for the fractionation of the positive dimension of schizotypy into subdimensions of PI and UE, and lend indirect support to dimensional or quasidimensional conceptions of psychosis. More specifically, they suggest that PI may be associated with alteration in contextual updating processes, and that UE may reflect altered sensory/early-attention (N100) mechanisms. The sex differences observed are consistent with those previously observed in individuals with schizophrenia.

Premature terminator analysis sheds light on a hidden world of bacterial transcriptional attenuation.

PubMed

Naville, Magali; Gautheret, Daniel

2010-01-01

Bacterial transcription attenuation occurs through a variety of cis-regulatory elements that control gene expression in response to a wide range of signals. The signal-sensing structures in attenuators are so diverse and rapidly evolving that only a small fraction have been properly annotated and characterized to date. Here we apply a broad-spectrum detection tool in order to achieve a more complete view of the transcriptional attenuation complement of key bacterial species. Our protocol seeks gene families with an unusual frequency of 5' terminators found across multiple species. Many of the detected attenuators are part of annotated elements, such as riboswitches or T-boxes, which often operate through transcriptional attenuation. However, a significant fraction of candidates were not previously characterized in spite of their unmistakable footprint. We further characterized some of these new elements using sequence and secondary structure analysis. We also present elements that may control the expression of several non-homologous genes, suggesting co-transcription and response to common signals. An important class of such elements, which we called mobile attenuators, is provided by 3' terminators of insertion sequences or prophages that may be exapted as 5' regulators when inserted directly upstream of a cellular gene. We show here that attenuators involve a complex landscape of signal-detection structures spanning the entire bacterial domain. We discuss possible scenarios through which these diverse 5' regulatory structures may arise or evolve.

Unusual dewetting of thin polymer films in liquid media containing a poor solvent and a nonsolvent.

PubMed

Xu, Lin; Sharma, Ashutosh; Joo, Sang Woo; Liu, Hui; Shi, Tongfei

2014-12-16

We investigate the control of pattern size and kinetics in spontaneous dewetting of thin polymer films (polystyrene) that are stable to thermal annealing by annealing in a poor solvent (acetone)/nonsolvent (ethanol or n-hexane) liquid mixture. Dewetting occurs by the formation and growth of circular holes that coalesce to form droplets. The influence of the nature and the volume fraction of the nonsolvents on the contact angle of polymer droplets, number density of holes, and the kinetics of holes formation and growth is studied. Addition of ethanol greatly increases the hole density and slows down the kinetics substantially, while affecting only a small change in wettability. n-Hexane addition shows an interesting nonmonotonic response in decreasing the hole density and contact angle in the volume fraction range of 0-0.3 but an opposite effect beyond that. Although the two nonsolvents chosen cannot by themselves induce dewetting, their relative affinity for the solid substrate vis-à-vis acetone can strongly influence the observed dewetting scenarios that are not understood by the existing theoretical considerations. n-Hexane, for example, has great affinity for silicon substrate. In addition to the changes in wettability, viscosity, and film interfacial tension engendered by the nonsolvents, the possibility of the formation of adsorbed liquid layers at the substrate-polymer interface, which can modify the interfacial friction and slippage, needs to be considered.

Disruption of the A-Kinase Anchoring Domain in Flagellar Radial Spoke Protein 3 Results in Unregulated Axonemal cAMP-dependent Protein Kinase Activity and Abnormal Flagellar Motility

PubMed Central

Gaillard, Anne R.; Fox, Laura A.; Rhea, Jeanne M.; Craige, Branch

2006-01-01

Biochemical studies of Chlamydomonas flagellar axonemes revealed that radial spoke protein (RSP) 3 is an A-kinase anchoring protein (AKAP). To determine the physiological role of PKA anchoring in the axoneme, an RSP3 mutant, pf14, was transformed with an RSP3 gene containing a mutation in the PKA-binding domain. Analysis of several independent transformants revealed that the transformed cells exhibit an unusual phenotype: a fraction of the cells swim normally; the remainder of the cells twitch feebly or are paralyzed. The abnormal/paralyzed motility is not due to an obvious deficiency of radial spoke assembly, and the phenotype cosegregates with the mutant RSP3. We postulated that paralysis was due to failure in targeting and regulation of axonemal cAMP-dependent protein kinase (PKA). To test this, reactivation experiments of demembranated cells were performed in the absence or presence of PKA inhibitors. Importantly, motility in reactivated cell models mimicked the live cell phenotype with nearly equal fractions of motile and paralyzed cells. PKA inhibitors resulted in a twofold increase in the number of motile cells, rescuing paralysis. These results confirm that flagellar RSP3 is an AKAP and reveal that a mutation in the PKA binding domain results in unregulated axonemal PKA activity and inhibition of normal motility. PMID:16571668

Estimating mortality rates of adult fish from entrainment through the propellers of river towboats

USGS Publications Warehouse

Gutreuter, S.; Dettmers, J.M.; Wahl, David H.

2003-01-01

We developed a method to estimate mortality rates of adult fish caused by entrainment through the propellers of commercial towboats operating in river channels. The method combines trawling while following towboats (to recover a fraction of the kills) and application of a hydrodynamic model of diffusion (to estimate the fraction of the total kills collected in the trawls). The sampling problem is unusual and required quantifying relatively rare events. We first examined key statistical properties of the entrainment mortality rate estimators using Monte Carlo simulation, which demonstrated that a design-based estimator and a new ad hoc estimator are both unbiased and converge to the true value as the sample size becomes large. Next, we estimated the entrainment mortality rates of adult fishes in Pool 26 of the Mississippi River and the Alton Pool of the Illinois River, where we observed kills that we attributed to entrainment. Our estimates of entrainment mortality rates were 2.52 fish/km of towboat travel (80% confidence interval, 1.00-6.09 fish/km) for gizzard shad Dorosoma cepedianum, 0.13 fish/km (0.00-0.41) for skipjack herring Alosa chrysochloris, and 0.53 fish/km (0.00-1.33) for both shovelnose sturgeon Scaphirhynchus platorynchus and smallmouth buffalo Ictiobus bubalus. Our approach applies more broadly to commercial vessels operating in confined channels, including other large rivers and intracoastal waterways.

Nitrogen Fractionation in Protoplanetary Disks from the H13CN/HC15N Ratio

NASA Astrophysics Data System (ADS)

Guzmán, V. V.; Öberg, K. I.; Huang, J.; Loomis, R.; Qi, C.

2017-02-01

Nitrogen fractionation is commonly used to assess the thermal history of solar system volatiles. With ALMA it is for the first time possible to directly measure {}14{{N}}/{}15{{N}} ratios in common molecules during the assembly of planetary systems. We present ALMA observations of the {{{H}}}13{CN} and {{HC}}15{{N}} J=3-2 lines at 0.″5 angular resolution, toward a sample of six protoplanetary disks, selected to span a range of stellar and disk structure properties. Adopting a typical {}12{{C}}/{}13{{C}} ratio of 70, we find comet-like {}14{{N}}/{}15{{N}} ratios of 80-160 in five of the disks (3 T Tauri and 2 Herbig Ae disks) and lack constraints for one of the T Tauri disks (IM Lup). There are no systematic differences between T Tauri and Herbig Ae disks, or between full and transition disks within the sample. In addition, no correlation is observed between disk-averaged D/H and {}14{{N}}/{}15{{N}} ratios in the sample. One of the disks, V4046 Sgr, presents unusually bright HCN isotopologue emission, enabling us to model the radial profiles of {{{H}}}13{CN} and {{HC}}15{{N}}. We find tentative evidence of an increasing {}14{{N}}/{}15{{N}} ratio with radius, indicating that selective photodissociation in the inner disk is important in setting the {}14{{N}}/{}15{{N}} ratio during planet formation.

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

Sills, Alison; Glebbeek, Evert; Chatterjee, Sourav

We created artificial color-magnitude diagrams of Monte Carlo dynamical models of globular clusters and then used observational methods to determine the number of blue stragglers in those clusters. We compared these blue stragglers to various cluster properties, mimicking work that has been done for blue stragglers in Milky Way globular clusters to determine the dominant formation mechanism(s) of this unusual stellar population. We find that a mass-based prescription for selecting blue stragglers will select approximately twice as many blue stragglers than a selection criterion that was developed for observations of real clusters. However, the two numbers of blue stragglers aremore » well-correlated, so either selection criterion can be used to characterize the blue straggler population of a cluster. We confirm previous results that the simplified prescription for the evolution of a collision or merger product in the BSE code overestimates their lifetimes. We show that our model blue stragglers follow similar trends with cluster properties (core mass, binary fraction, total mass, collision rate) as the true Milky Way blue stragglers as long as we restrict ourselves to model clusters with an initial binary fraction higher than 5%. We also show that, in contrast to earlier work, the number of blue stragglers in the cluster core does have a weak dependence on the collisional parameter Γ in both our models and in Milky Way globular clusters.« less

Simulation analysis of a wildfire suppression system

Treesearch

Abílio Pereira Pacheco; João Claro; Tiago Oliveira

2013-01-01

Rekindles and false alarms are unusually high in the Portuguese wildfire management system, representing a high burden on suppression resources in particular, and fire management resources in general. In 20,049 occurrences that the suppression system handled in the summer of 2010, 12.5% were false alarms and 15.0% were rekindles. We present a discreteevent simulation...

The panchromatic Hubble Andromeda treasury. VII. The steep mid-ultraviolet to near-infrared extinction curve in the central 200 pc of the M31 Bulge

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

Dong, Hui; Lauer, Tod R.; Olsen, Knut

We measure the extinction curve in the central 200 pc of M31 at mid-ultraviolet to near-infrared wavelengths (from 1928 Å to 1.5 μm), using Swift/UVOT and Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3)/Advanced Camera for Surveys (ACS) observations in 13 bands. Taking advantage of the high angular resolution of the HST/WFC3 and ACS detectors, we develop a method to simultaneously determine the relative extinction and the fraction of obscured starlight for five dusty complexes located in the circumnuclear region. The extinction curves of these clumps (R{sub V} = 2.4-2.5) are steeper than the average Galactic one (R{sub V}more » = 3.1), but are similar to optical and near-infrared curves recently measured toward the Galactic bulge (R{sub V} ∼ 2.5). This similarity suggests that steep extinction curves may be common in the inner bulge of galaxies. In the ultraviolet, the extinction curves of these clumps are also unusual. We find that one dusty clump (size < 2 pc) exhibits a strong UV bump (extinction at 2175 Å), more than three standard deviation higher than that predicted by common models. Although the high stellar metallicity of the M31 bulge indicates that there are sufficient carbon and silicon to produce large dust grains, the grains may have been destroyed by supernova explosions or past activity of the central supermassive black hole, resulting in the observed steepened extinction curve.« less

Unexpected Magnetic Domain Behavior in LTP-MnBi

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

Nguyen, PK; Jin, S; Berkowitz, AE

2013-07-01

Low-temperature-phase MnBi (LTP-MnBi) has attracted much interest as a potential rare-earth-free permanent magnet material because of its high uniaxial magnetocrystalline anisotropy at room temperature, K approximate to 10(7) ergs/cc, and the unusual increase of anisotropy with increasing temperature, with an accompanying increasing coercive force (H-C) with temperature. However, due to the complex Mn-Bi phase diagram, bulk samples of LTP-MnBi with the optimum saturation moment, similar to 75-76 emu/g have been achieved only with zone-refined single crystals. We have prepared polycrystalline samples of LTP-MnBi by induction melting and annealing at 300 degrees C. The moment in 70 kOe is 73.5 emu/g,more » but H-C is only 50 Oe. This is quite surprising-the high saturation moment indicates the dominating presence of LTP-MnBi. Therefore, an H-C c of some significant fraction of 2K/M-S approximate to 30 kOe would seem reasonable in this polycrystalline sample. By examining "Bitter" patterns, we show that the sample is composed of similar to 50 - 100 mu m crystallites. The randomly oriented crystallites exhibit the variety of magnetic domain structures and orientations expected from the hexagonal-structured MnBi with its strong uniaxial anisotropy. Clearly, the reversal of magnetization in the sample proceeds by the low-field nucleation of reversed magnetization in each crystallite, rather than by a wall-pinning mechanism. When the annealed sample was milled into fine particles, H-C increased by several orders of magnitude, as expected.« less

Inequality in fertility rate and modern contraceptive use among Ghanaian women from 1988–2008

PubMed Central

2013-01-01

Background In most resource poor countries, particularly sub-Saharan Africa, modern contraceptive use and prevalence is unusually low and fertility is very high resulting in rapid population growth and high maternal mortality and morbidity. Current evidence shows slow progress in expanding the use of contraceptives by women of low socioeconomic status and insufficient financial commitment to family planning programs. We examined gaps and trends in modern contraceptive use and fertility within different socio-demographic subgroups in Ghana between 1988 and 2008. Methods We constructed a database using the Women’s Questionnaire from the Ghana Demographic and Health Survey (GDHS) 1988, 1993, 1998, 2003 and 2008. We applied regression-based Total Attributable Fraction (TAF); we also calculated the Relative and Slope Indices of Inequality (RII and SII) to complement the TAF in our investigation. Results Equality in use of modern contraceptives increased from 1988 to 2008. In contrast, inequality in fertility rate increased from 1988 to 2008. It was also found that rural–urban residence gap in the use of modern contraceptive methods had almost disappeared in 2008, while education and income related inequalities remained. Conclusions One obvious observation is that the discrepancy between equality in use of contraceptives and equality in fertility must be addressed in a future revision of policies related to family planning. Otherwise this could be a major obstacle for attaining further progress in achieving the Millennium Development Goal (MDG) 5. More research into the causes of the unfortunate discrepancy is urgently needed. There still exist significant education and income related inequalities in both parameters that need appropriate action. PMID:23718745

Inequality in fertility rate and modern contraceptive use among Ghanaian women from 1988-2008.

PubMed

Asamoah, Benedict O; Agardh, Anette; Ostergren, Per-Östergren

2013-05-29

In most resource poor countries, particularly sub-Saharan Africa, modern contraceptive use and prevalence is unusually low and fertility is very high resulting in rapid population growth and high maternal mortality and morbidity. Current evidence shows slow progress in expanding the use of contraceptives by women of low socioeconomic status and insufficient financial commitment to family planning programs. We examined gaps and trends in modern contraceptive use and fertility within different socio-demographic subgroups in Ghana between 1988 and 2008. We constructed a database using the Women's Questionnaire from the Ghana Demographic and Health Survey (GDHS) 1988, 1993, 1998, 2003 and 2008. We applied regression-based Total Attributable Fraction (TAF); we also calculated the Relative and Slope Indices of Inequality (RII and SII) to complement the TAF in our investigation. Equality in use of modern contraceptives increased from 1988 to 2008. In contrast, inequality in fertility rate increased from 1988 to 2008. It was also found that rural-urban residence gap in the use of modern contraceptive methods had almost disappeared in 2008, while education and income related inequalities remained. One obvious observation is that the discrepancy between equality in use of contraceptives and equality in fertility must be addressed in a future revision of policies related to family planning. Otherwise this could be a major obstacle for attaining further progress in achieving the Millennium Development Goal (MDG) 5. More research into the causes of the unfortunate discrepancy is urgently needed. There still exist significant education and income related inequalities in both parameters that need appropriate action.

Change in Unusually Hot and Cold Temperatures in the Contiguous 48 States, 1948-2015

EPA Pesticide Factsheets

This map shows trends in unusually hot and cold temperatures at individual weather stations that have operated consistently since 1948. In this case, the term ??unusually hot?? refers to a daily maximum temperature that is hotter than the 95th percentile temperature during the 1948??2015 period. Thus, the maximum temperature on a particular day at a particular station would be considered ??unusually hot?? if it falls within the warmest 5 percent of measurements at that station during the 1948??2015 period. The map shows changes in the total number of days per year that were hotter than the 95th percentile. Red upward-pointing symbols show where these unusually hot days are becoming more common. Blue downward-pointing symbols show where unusually hot days are becoming less common. For more information: www.epa.gov/climatechange/science/indicators

2004 EW95: A Phyllosilicate-bearing Carbonaceous Asteroid in the Kuiper Belt

NASA Astrophysics Data System (ADS)

Seccull, Tom; Fraser, Wesley C.; Puzia, Thomas H.; Brown, Michael E.; Schönebeck, Frederik

2018-03-01

Models of the Solar System’s dynamical evolution predict the dispersal of primitive planetesimals from their formative regions among the gas-giant planets due to the early phases of planetary migration. Consequently, carbonaceous objects were scattered both into the outer asteroid belt and out to the Kuiper Belt. These models predict that the Kuiper Belt should contain a small fraction of objects with carbonaceous surfaces, though to date, all reported visible reflectance spectra of small Kuiper Belt Objects (KBOs) are linear and featureless. We report the unusual reflectance spectrum of a small KBO, (120216) 2004 EW95, exhibiting a large drop in its near-UV reflectance and a broad shallow optical absorption feature centered at ∼700 nm, which is detected at greater than 4σ significance. These features, confirmed through multiple epochs of spectral photometry and spectroscopy, have respectively been associated with ferric oxides and phyllosilicates. The spectrum bears striking resemblance to those of some C-type asteroids, suggesting that 2004 EW95 may share a common origin with those objects. 2004 EW95 orbits the Sun in a stable mean motion resonance with Neptune, at relatively high eccentricity and inclination, suggesting it may have been emplaced there by some past dynamical instability. These results appear consistent with the aforementioned model predictions and are the first to show a reliably confirmed detection of silicate material on a small KBO.

Radial Velocity and Metallicity Determinations for Remote Globular Clusters in M31 and M33

NASA Astrophysics Data System (ADS)

Ferguson, Annette; Barmby, Pauline; Cote, Pat; Harris, Bill; Huxor, Avon; Mackey, Dougal; Puzia, Thomas

2009-08-01

We propose to determine radial velocities and metallicities for a sample of ~ 20 remote globular clusters (GCs) which we have discovered in the outer halos of the Local Group galaxies M31 and M33. Most of these objects have been uncovered in the course of the PAndAs survey, an international collaboration which is using CFHT/MegaPrime to map more than 300 square degrees in the g and i bands around M31 and M33. The target clusters, all of which have been identified from high- quality imaging (typically ≲ 0.8'' seeing), lie at projected radii of up to 130 kpc from M31 and 30 kpc from M33 and thus lie significantly beyond all previously-known GCs in these systems. Rather intriguingly, many of the new discoveries exhibit either possible associations with halo tidal streams, or show unusual spatial anisotropies with respect to their host galaxy. Velocity and metallicity data for these objects will provide a detailed characterization of the ensemble properties of the outer halo GC populations, and, through the search for kinematic and metallicity correlations within groups of GCs, help determine what fraction of these objects can be attributed to either late or ongoing accretion events. Ultimately, these data will also provide a basis for improved dynamical mass estimates of both galaxies.

Anticoagulant and antithrombotic evaluation of native fucosylated chondroitin sulfates and their derivatives as selective inhibitors of intrinsic factor Xase.

PubMed

Wu, Mingyi; Wen, Dandan; Gao, Na; Xiao, Chuang; Yang, Lian; Xu, Li; Lian, Wu; Peng, Wenlie; Jiang, Jianmin; Zhao, Jinhua

2015-03-06

Fucosylated chondroitin sulfate (FCS), a structurally unusual glycosaminoglycan, has distinct anticoagulant properties, and is an especially strong inhibitor of the intrinsic factor Xase (anti-Xase). To obtain a highly selective inhibitor of human Xase, we purified six native FCSs with various sulfation patterns, prepared a series of FCS derivatives, and then elucidated the relationship between the structures and the anticoagulant activities of FCSs. FCSs 1-3 containing higher Fuc2S4S exhibit stronger AT-dependent anti-IIa activities, whereas 4-6 containing more Fuc3S4S produce potent HCII-dependent anti-IIa activities. Saccharides containing a minimum of 6-8 trisaccharide units, free carboxyl groups, and full fucosylation of GlcA may be required for potent anti-Xase activity, and approximately six trisaccharide units and partial fucosylation of GlcA may contribute to potent HCII-dependent activity. Decreasing of the molecular weights markedly reduces their AT-dependent anti-IIa activities, and even eliminates human platelet and factor XII activation. Furthermore, in vitro and in vivo studies suggested that fractions of 6-12 kDa may be very promising compounds as putative selective intrinsic Xase inhibitors with antithrombotic action, but without the consequences of major bleeding and factor XII activation. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Erroneous HbA1c results in a patient with elevated HbC and HbF.

PubMed

Adekanmbi, Joy; Higgins, Trefor; Rodriguez-Capote, Karina; Thomas, Dylan; Winterstein, Jeffrey; Dixon, Tara; Gifford, Jessica L; Krause, Richard; Venner, Allison A; Clarke, Gwen; Estey, Mathew P

2016-11-01

HbA1c is used in the diagnosis and monitoring of diabetes mellitus (DM). Interference from hemoglobin variants is a well-described phenomenon, particularly with HPLC-based methods. While immunoassays may generate more reliable HbA1c results in the presence of some variants, these methods are susceptible to negative interference from high concentrations of HbF. We report a case where an accurate HbA1c result could not be obtained by any available method due to the presence of a compound hemoglobinopathy. HbA1c was measured by HPLC, immunoassay, and capillary electrophoresis. Hemoglobinopathy investigation consisted of a CBC, hemoglobin fractionation by HPLC and electrophoresis, and molecular analysis. HbA1c analysis by HPLC and capillary electrophoresis gave no result. Analysis by immunoassay yielded HbA1c results of 5.9% (Siemens DCA 2000+) and 5.1% (Roche Integra), which were inconsistent with other markers of glycemic control. Hemoglobinopathy investigation showed HbC with the hereditary persistence of fetal hemoglobin-2 Ghana deletion. Reliable HbA1c results may be unobtainable in the presence of some hemoglobinopathies. HPLC and capillary electrophoresis alerted the laboratory to the presence of an unusual hemoglobinopathy. Immunoassays generated falsely low results without warning, which could lead to missed diagnoses and under treatment of patients with DM. Copyright © 2016 Elsevier B.V. All rights reserved.

On the significance of δ13C correlations in ancient sediments

NASA Astrophysics Data System (ADS)

Derry, Louis A.

2010-08-01

A graphical analysis of the correlations between δc and ɛTOC was introduced by Rothman et al. (2003) to obtain estimates of the carbon isotopic composition of inputs to the oceans and the organic carbon burial fraction. Applied to Cenozoic data, the method agrees with independent estimates, but with Neoproterozoic data the method yields results that cannot be accommodated with standard models of sedimentary carbon isotope mass balance. We explore the sensitivity of the graphical correlation method and find that the variance ratio between δc and δo is an important control on the correlation of δc and ɛ. If the variance ratio σc/ σo ≥ 1 highly correlated arrays very similar to those obtained from the data are produced from independent random variables. The Neoproterozoic data shows such variance patterns, and the regression parameters for the Neoproterozoic data are statistically indistinguishable from the randomized model at the 95% confidence interval. The projection of the data into δc- ɛ space cannot distinguish between signal and noise, such as post-depositional alteration, under these circumstances. There appears to be no need to invoke unusual carbon cycle dynamics to explain the Neoproterozoic δc- ɛ array. The Cenozoic data have σc/ σo < 1 and the δc vs. ɛ correlation is probably geologically significant, but the analyzed sample size is too small to yield statistically significant results.

Left ventricle pseudoaneurysm in a transplanted heart from a car crash victim donor.

PubMed

Urbanowicz, Tomasz; Katarzyński, Sławomir; Puślecki, Mateusz; Budniak, Wiktor; Araszkiewicz, Aleksander; Łanocha, Magdalena; Pyda, Małgorzata; Straburzyńska-Migaj, Ewa; Jemielity, Marek

2014-06-26

Pseudoaneurysm is a very rare and unusual form of myocardial rupture, with complications such as chest trauma, inflammation, acute myocardial infarction, and infection. Although this rare complication has already been reported, it has never been found in a transplanted patient. We present the case of a 54-year-old women waiting on the urgent list who underwent heart transplantation. The donor of the organ died in a car accident. Although preoperative echocardiography had not revealed any signs of heart injury, a superficial small (3 × 3 mm hematoma) was detected on harvesting. After implantation, intraoperative echocardiography was satisfactory, with no signs of wall motion disturbances, and left ventricle ejection fraction was estimated at 50%. The postoperative period was uneventful. Three weeks after surgery, a left ventricle pseudoaneurysm was found on routine MRI. The aneurysm wall consisted of only an epicardial layer. There was an 8-mm-wide gap in the myocardial wall next to the endocardium and with the width of 4 mm beneath the epicardium. On repeated MRI performed 3 months thereafter, the pseudoaneurysm was filled by thrombus. The presented case illustrates the necessity of careful inspection of the organ reported for transplantation from a donor who died from high-speed motor vehicle crash injuries. Additional diagnostic steps like MRI imaging are obligatory after transplantation, especially when the organ was harvested from a motor vehicle crash victim.

STELLAR MEMBERSHIP AND DUSTY DEBRIS DISKS IN THE {alpha} PERSEI CLUSTER

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

Zuckerman, B.; Melis, Carl; Rhee, Joseph H.

2012-06-10

Because of its proximity to the Galactic plane, reliable identification of members of the {alpha} Persei cluster is often problematic. Based primarily on membership evaluations contained in six published papers, we constructed a mostly complete list of high-fidelity members of spectral type G and earlier that lie within 3 arc degrees of the cluster center. {alpha} Persei was the one nearby, rich, young open cluster not surveyed with the Spitzer Space Telescope. We examined the first and final data releases of the Wide-field Infrared Survey Explorer and found 11, or perhaps 12, {alpha} Per cluster members that have excess mid-infraredmore » emission above the stellar photosphere attributable to an orbiting dusty debris disk. The most unusual of these is V488 Per, a K-type star with an excess IR luminosity 16% (or more) of the stellar luminosity; this is a larger excess fraction than that of any other known dusty main-sequence star. Much of the dust that orbits V488 Per is at a temperature of {approx}800 K; if these grains radiate like blackbodies, then they lie only {approx}0.06 AU from the star. The dust is probably the aftermath of a collision of two planetary embryos or planets with small semimajor axes; such orbital radii are similar to those of many of the transiting planets discovered by the Kepler satellite.« less

Complete Chloroplast Genome of the Wollemi Pine (Wollemia nobilis): Structure and Evolution.

PubMed

Yap, Jia-Yee S; Rohner, Thore; Greenfield, Abigail; Van Der Merwe, Marlien; McPherson, Hannah; Glenn, Wendy; Kornfeld, Geoff; Marendy, Elessa; Pan, Annie Y H; Wilton, Alan; Wilkins, Marc R; Rossetto, Maurizio; Delaney, Sven K

2015-01-01

The Wollemi pine (Wollemia nobilis) is a rare Southern conifer with striking morphological similarity to fossil pines. A small population of W. nobilis was discovered in 1994 in a remote canyon system in the Wollemi National Park (near Sydney, Australia). This population contains fewer than 100 individuals and is critically endangered. Previous genetic studies of the Wollemi pine have investigated its evolutionary relationship with other pines in the family Araucariaceae, and have suggested that the Wollemi pine genome contains little or no variation. However, these studies were performed prior to the widespread use of genome sequencing, and their conclusions were based on a limited fraction of the Wollemi pine genome. In this study, we address this problem by determining the entire sequence of the W. nobilis chloroplast genome. A detailed analysis of the structure of the genome is presented, and the evolution of the genome is inferred by comparison with the chloroplast sequences of other members of the Araucariaceae and the related family Podocarpaceae. Pairwise alignments of whole genome sequences, and the presence of unique pseudogenes, gene duplications and insertions in W. nobilis and Araucariaceae, indicate that the W. nobilis chloroplast genome is most similar to that of its sister taxon Agathis. However, the W. nobilis genome contains an unusually high number of repetitive sequences, and these could be used in future studies to investigate and conserve any remnant genetic diversity in the Wollemi pine.

The Multi-Layer Variable Absorbers in NGC 1365 Revealed by XMM-Newton and NuSTAR

NASA Technical Reports Server (NTRS)

Rivers, E.; Risaliti, G.; Walton, D. J.; Harrison, F.; Arevalo, P.; Baur, F. E.; Boggs, S. E.; Brenneman, L. W.; Brightman, M.; Zhang, W. W.

2015-01-01

Between 2012 July and 2013 February, NuSTAR and XMM-Newton performed four long-look joint observations of the type 1.8 Seyfert, NGC 1365. We have analyzed the variable absorption seen in these observations in order to characterize the geometry of the absorbing material. Two of the observations caught NGC 1365 in an unusually low absorption state, revealing complexity in the multi-layer absorber that had previously been hidden. We find the need for three distinct zones of neutral absorption in addition to the two zones of ionized absorption and the Compton-thick torus previously seen in this source. The most prominent absorber is likely associated with broad-line region clouds with column densities of around approximately 10 (sup 23) per square centimeter and a highly clumpy nature as evidenced by an occultation event in 2013 February. We also find evidence of a patchy absorber with a variable column around approximately 10 (sup 22) per square centimeter and a line-of-sight covering fraction of 0.3-0.9, which responds directly to the intrinsic source flux, possibly due to a wind geometry. A full-covering, constant absorber with a low column density of approximately 1 by 10 (sup 22) per square centimeter is also present, though the location of this low density haze is unknown.

Climate, not conflict, explains extreme Middle East dust storm

DOE PAGES

Parolari, Anthony J.; Li, Dan; Bou-Zeid, Elie; ...

2016-11-08

The recent dust storm in the Middle East (Sepember 2015) was publicized in the media as a sign of an impending 'Dust Bowl.' Its severity, demonstrated by extreme aerosol optical depth in the atmosphere in the 99th percentile compared to historical data, was attributed to the ongoing regional conflict. However, surface meteorological and remote sensing data, as well as regional climate model simulations, support an alternative hypothesis: the historically unprecedented aridity played a more prominent role, as evidenced by unusual climatic and meteorological conditions prior to and during the storm. Remotely sensed normalized difference vegetation index demonstrates that vegetation covermore » was high in 2015 relative to the prior drought and conflict periods, suggesting that agricultural activity was not diminished during that year, thus negating the media narrative. Instead, meteorological simulations using the Weather Research and Forecasting (WRF) model show that the storm was associated with a cyclone and 'Shamal' winds, typical for dust storm generation in this region, that were immediately followed by an unusual wind reversal at low levels that spread dust west to the Mediterranean Coast. These unusual meteorological conditions were aided by a significant reduction in the critical shear stress due to extreme dry and hot conditions, thereby enhancing dust availability for erosion during this storm. Concluding, unusual aridity, combined with unique synoptic weather patterns, enhanced dust emission and westward long-range transport across the region, thus generating the extreme storm.« less

Lantibiotic engineering: molecular characterization and exploitation of lantibiotic-synthesizing enzymes for peptide engineering.

PubMed

Nagao, Jun-ichi; Aso, Yuji; Shioya, Kouki; Nakayama, Jiro; Sonomoto, Kenji

2007-01-01

Lanthionine-containing peptide antibiotics called lantibiotics are produced by a large number of Gram-positive bacteria. Nukacin ISK-1 produced by Staphylococcus warneri ISK-1 is type-A(II) lantibiotic. Ribosomally synthesized nukacin ISK-1 prepeptide (NukA) consists of an N-terminal leader peptide followed by a C-terminal propeptide moiety that undergoes several post-translational modification events including unusual amino acid formation by the modification enzyme NukM, cleavage of leader peptide and export by the dual functional ABC transporter NukT, finally yielding a biologically active peptide. Unusual amino acids in lantibiotics contribute to biological activity and also structural stability against proteases. Thus, lantibiotic-synthesizing enzymes have a high potentiality for peptide engineering by introduction of unusual amino acids into desired peptides with altering biological and physicochemical properties, e.g., activity and stability, termed lantibiotic engineering. We report the establishment of a heterologous expression of nukacin ISK-1 biosynthetic gene cluster by the nisin-controlled expression system and discuss our recent progress in understanding of the biosynthetic enzymes for nukacin ISK-1 such as localization, molecular interaction in biophysical and biochemical aspects. Substrate specificity of the lantibiotic-synthesizing enzymes was evaluated by complementation of the biosynthetic enzymes (LctM and LctT) of closely related lantibiotic lacticin 481 for nukacin ISK-1 biosynthesis. We further explored a rapid and powerful tool for introduction of unusual amino acids by co-expression of hexa-histidine-tagged NukA and NukM in Escherichia coli.

Unusual tremor syndromes: know in order to recognise.

PubMed

Ure, Robert J; Dhanju, Sanveer; Lang, Anthony E; Fasano, Alfonso

2016-11-01

Tremor is a common neurological condition in clinical practice; yet, few syndromes are widely recognised and discussed in the literature. As a result, there is an overdiagnosis of well-known causes, such as essential tremor. Many important unusual syndromes should be considered in the differential diagnosis of patients with tremor. The objective of this review is to provide broad clinical information to aid in the recognition and treatment of various unusual tremor syndromes in the adult and paediatric populations. The review comprised of a comprehensive online search using PubMed, Ovid database and Google Scholar to identify the available literature for each unusual tremor syndrome. The review includes fragile X-associated tremor/ataxia syndrome, spinocerebellar ataxia type 12, tremors caused by autosomal recessive cerebellar ataxias, myorhythmia, isolated tongue tremor, Wilson's disease, slow orthostatic tremor, peripheral trauma-induced tremor, tardive tremor and rabbit syndrome, paroxysmal tremors (hereditary chin tremor, bilateral high-frequency synchronous discharges, head tremor, limb-shaking transient ischaemic attack), bobble-head doll syndrome, spasmus nutans and shuddering attacks. Rare tremors generally present with an action tremor and a variable combination of postural and kinetic components with resting tremors less frequently seen. The phenomenology of myorhythmia is still vague and a clinical definition is proposed. The recognition of these entities should facilitate the correct diagnosis and guide the physician to a prompt intervention. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.