12 research outputs found

    Results of multidisciplinary survey in the Laptev Sea in August-September, 2015

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    Data on oceanographic conditions and species composition of plankton, benthic and demersal fish and invertebrates are presented, obtained in the complex survey over the external shelf of the Laptev Sea in August-September 2015. The zooplankton abundance was low, with only local increases up to 400 mg/m3. Species diversity of fish and nekton invertebrates in the bottom trawl catches was low, too: 26 fish species and 2 species of cephalopods. Mean biomass of fish was estimated as 4.3 t/km2 (in total 132. 103 t within the surveyed area of 30,500 km2). All fish species were distributed sparse. Arctic cod was the most abundant and occurred over the whole surveyed area, with large-sized fish dominating at the bottom and medium-sized (9-15 cm) fish - in the pelagic layer, other commercial species were greenland halibut and deepwater redfish caught on the continental slope. Bottom invertebrates in trawl catches were presented by 6 species of shrimp and 12 taxonomic groups of different rank, with predominance of starfish, brittle stars and sponges; gastropods were represented by 11 species, with Neptunea heros dominating by mass (42 %). Macrobenthos in samples of the bottom sampler was presented by 20 taxonomic groups, with predominance of polychaetes, bivalves and sipunculoids

    Amgaite, Tl3+2Te6+O6, a New Mineral from the Khokhoyskoe Gold Deposit, Eastern Siberia, Russia

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    The new mineral amgaite was discovered at the Khokhoyskoe gold deposit, 120 km W of Aldan town, Aldanskiy District, Sakha Republic (Yakutia), Eastern Siberia, Russia. Amgaite forms fine-grained colloform aggregates up to 0.05 mm across, and is often intimately intergrown with avicennite, unidentified carbonates and antimonates of Tl. Other associated minerals include gold, silver, acanthite, arsenopyrite, pyrite, berthierite, chalcocite, weissbergite, chlorargyrite, calcite, quartz, goethite etc. Amgaite is dark reddish brown to black. It has submetallic luster, black streak, brittle tenacity and conchoidal fracture. Its density calculated from the empirical formula and powder XRD data is 8.358 g/cm3. Its Mohs’ hardness is ca. 1.5–2. Optically, amgaite is uniaxial. In reflected light, it is gray with a bluish shade, very weakly anisotropic with rare brownish red internal reflections. Reflectance values for the four COM wavelengths [Rmin, Rmax (%)(λ in nm)] are: 13.5, 14.2 (470); 12.7, 13.2 (546); 12.3, 12.7 (589); and 11.7, 12.3 (650). The Raman spectrum shows bands of Te–O and Tl–O bonds and confirms the absence in amgaite of H2O, OH–, CO32– groups and B–O bonds. The chemical composition is (electron microprobe, wt.%): MgO 0.43, CaO 1.62, Fe2O3 0.36, Tl2O3 66.27, Sb2O5 3.48, TeO3 27.31, total 99.47. The empirical formula based on 6 O apfu is Tl3+1.74Ca0.17Mg0.06Fe3+0.03Te6+0.93Sb5+0.13O6. Amgaite is trigonal, space group P321; unit-cell parameters are as follows: a = 9.0600(9), c = 4.9913(11) Å, V = 354.82(8) Å3, Z = 3. The strongest lines of the powder X-ray diffraction pattern [dobs, Å (I, %) (hkl)] are as follows: 3.352 (100) (111), 3.063 (15) (201), 2.619 (49) (300), 2.065 (18) (221), 1.804 (28) (302), 1.697 (8) (321), 1.625 (9) (411). The crystal structure of amgaite is the same as of synthetic Tl3+2Te6+O6. The new mineral is named after the Amga River, the basin of which hosts the type locality, Khokhoyskoe occurrence. The type material is deposited in the collections of the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia, with the registration number 5773/1

    Protective Effect of Dinitrosyl Iron Complexes with Glutathione in Red Blood Cell Lysis Induced by Hypochlorous Acid

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    Hypochlorous acid (HOCl), one of the major precursors of free radicals in body cells and tissues, is endowed with strong prooxidant activity. In living systems, dinitrosyl iron complexes (DNIC) with glutathione ligands play the role of nitric oxide donors and possess a broad range of biological activities. At micromolar concentrations, DNIC effectively inhibit HOCl-induced lysis of red blood cells (RBCs) and manifest an ability to scavenge alkoxyl and alkylperoxyl radicals generated in the reaction of HOCl with tert-butyl hydroperoxide. DNIC proved to be more effective cytoprotective agents and organic free radical scavengers in comparison with reduced glutathione (GSH). At the same time, the kinetics of HOCl-induced oxidation of glutathione ligands in DNIC is slower than in the case of GSH. HOCl-induced oxidative conversions of thiolate ligands cause modification of DNIC, which manifests itself in inclusion of other ligands. It is suggested that the strong inhibiting effect of DNIC with glutathione on HOCl-induced lysis of RBCs is determined by their antioxidant and regulatory properties

    Erratum to: Search for B decays to final states with the eta (c) meson (vol 06, 132, 2015)

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    We report a search for BB decays to selected final states with the ηc\eta_c meson: B±K±ηcπ+πB^{\pm}\to K^{\pm}\eta_c\pi^+\pi^-, B±K±ηcωB^{\pm}\to K^{\pm}\eta_c\omega, B±K±ηcηB^{\pm}\to K^{\pm}\eta_c\eta and B±K±ηcπ0B^{\pm}\to K^{\pm}\eta_c\pi^0. The analysis is based on 772×106772\times 10^6 BBˉB\bar{B} pairs collected at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. We set 90\% confidence level upper limits on the branching fractions of the studied BB decay modes, independent of intermediate resonances, in the range (0.65.3)×104(0.6-5.3)\times 10^{-4}. We also search for molecular-state candidates in the D0Dˉ0Dˉ0D0D^0\bar{D}^{*0}-\bar{D}^0D^{*0}, D0Dˉ0+Dˉ0D0D^0\bar{D}^0+\bar{D}^0D^0 and D0Dˉ0+Dˉ0D0D^{*0}\bar{D}^{*0}+\bar{D}^{*0}D^{*0} combinations, neutral partners of the Z(3900)±Z(3900)^{\pm} and Z(4020)±Z(4020)^{\pm}, and a poorly understood state X(3915)X(3915) as possible intermediate states in the decay chain, and set 90\% confidence level upper limits on the product of branching fractions to the mentioned intermediate states and decay branching fractions of these states in the range (0.66.9)×105(0.6-6.9)\times 10^{-5}

    Review of Solar Energetic Particle Models

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    Solar Energetic Particles (SEP) events are interesting from a scientific perspective as they are the product of a broad set of physical processes from the corona out through the extent of the heliosphere, and provide insight into processes of particle acceleration and transport that are widely applicable in astrophysics. From the operations perspective, SEP events pose a radiation hazard for aviation, electronics in space, and human space exploration, in particular for missions outside of the Earth’s protective magnetosphere including to the Moon and Mars. Thus, it is critical to imific understanding of SEP events and use this understanding to develop and improve SEP forecasting capabilities to support operations. Many SEP models exist or are in development using a wide variety of approaches and with differing goals. These include computationally intensive physics-based models, fast and light empirical models, machine learning-based models, and mixed-model approaches. The aim of this paper is to summarize all of the SEP models currently developed in the scientific community, including a description of model approach, inputs and outputs, free parameters, and any published validations or comparisons with data

    Measurement of the branching fractions for Cabibbo-suppressed decays D+K+Kπ+π0D^{+}\to K^{+} K^{-}\pi^{+}\pi^{0} and D(s)+K+ππ+π0D_{(s)}^{+}\to K^{+}\pi^{-}\pi^{+}\pi^{0} at Belle

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    International audienceWe present measurements of the branching fractions for the singly Cabibbo-suppressed decays D+K+Kπ+π0D^+\to K^{+}K^{-}\pi^{+}\pi^{0} and Ds+K+ππ+π0D_s^{+}\to K^{+}\pi^{-}\pi^{+}\pi^{0}, and the doubly Cabibbo-suppressed decay D+K+ππ+π0D^{+}\to K^{+}\pi^{-}\pi^{+}\pi^{0}, based on 980 fb1{\rm fb}^{-1} of data recorded by the Belle experiment at the KEKB e+ee^{+}e^{-} collider. We measure these modes relative to the Cabibbo-favored modes D+Kπ+π+π0D^{+}\to K^{-}\pi^{+}\pi^{+}\pi^{0} and Ds+K+Kπ+π0D_s^{+}\to K^{+}K^{-}\pi^{+}\pi^{0}. Our results for the ratios of branching fractions are B(D+K+Kπ+π0)/B(D+Kπ+π+π0)=(11.32±0.13±0.26)%B(D^{+}\to K^{+}K^{-}\pi^{+}\pi^{0})/B(D^{+}\to K^{-}\pi^{+}\pi^{+}\pi^{0}) = (11.32 \pm 0.13 \pm 0.26)\%, B(D+K+ππ+π0)/B(D+Kπ+π+π0)=(1.68±0.11±0.03)%B(D^{+}\to K^{+}\pi^{-}\pi^{+}\pi^{0})/B(D^{+}\to K^{-}\pi^{+}\pi^{+}\pi^{0}) = (1.68 \pm 0.11\pm 0.03)\%, and B(Ds+K+ππ+π0)/B(Ds+K+Kπ+π0)=(17.13±0.62±0.51)%B(D_s^{+}\to K^{+}\pi^{-}\pi^{+}\pi^{0})/B(D_s^{+}\to K^{+}K^{-}\pi^{+}\pi^{0}) = (17.13 \pm 0.62 \pm 0.51)\%, where the uncertainties are statistical and systematic, respectively. The second value corresponds to (5.83±0.42)×tan4θC(5.83\pm 0.42)\times\tan^4\theta_C, where θC\theta_C is the Cabibbo angle; this value is larger than other measured ratios of branching fractions for a doubly Cabibbo-suppressed charm decay to a Cabibbo-favored decay. Multiplying these results by world average values for B(D+Kπ+π+π0)B(D^{+}\to K^{-}\pi^{+}\pi^{+}\pi^{0}) and B(Ds+K+Kπ+π0)B(D_s^{+}\to K^{+}K^{-}\pi^{+}\pi^{0}) yields B(D+K+Kπ+π0)=(7.08±0.08±0.16±0.20)×103B(D^{+}\to K^{+}K^{-}\pi^{+}\pi^{0})= (7.08\pm 0.08\pm 0.16\pm 0.20)\times10^{-3}, B(D+K+ππ+π0)=(1.05±0.07±0.02±0.03)×103B(D^{+}\to K^{+}\pi^{-}\pi^{+}\pi^{0})= (1.05\pm 0.07\pm 0.02\pm 0.03)\times10^{-3}, and B(Ds+K+ππ+π0)=(9.44±0.34±0.28±0.32)×103B(D_s^{+}\to K^{+}\pi^{-}\pi^{+}\pi^{0}) = (9.44\pm 0.34\pm 0.28\pm 0.32)\times10^{-3}, where the third uncertainty is due to the branching fraction of the normalization mode. The first two results are consistent with, but more precise than, the current world averages. The last result is the first measurement of this branching fraction
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