580 research outputs found

    Magmatic overpressures, volatile exsolution and potential explosivity of fissure eruptions inferred via dike aspect ratios

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    Buoyant magmas abundant in exsolved volatiles (bubbles) drive the rapid upward-propagation of feeder dikes from magma chambers. The consequence of a feeder dike reaching the surface can result in an explosive volcanic eruption depending, partly, on the retention of volatiles. Therefore, timely detection of the vesicularity and overpressure of the magma during feeder dike ascent is critical for the prediction of the explosivity of any future eruption. In this study, we evaluated the explosivity of eruptions based on field investigations of the erupted products and the overpressure of magma in the conduit based on the dimensions of exposed feeder dikes. We found a positive correlation between the explosivity of eruptions and the magma overpressure generated in the conduit during recent fissure eruptions of Miyakejima volcano. Because the buoyancy of low-density magma produces positive overpressure at the dike’s top, feeder dikes with highly-vesiculated magmas possess high amounts of overpressure. An enlargement of the opening width of a feeder dike by magmatic overpressure results in a higher flux of vesiculated magma, which causes vigorous explosive activity. Our results suggest the possibility of forecasting the explosivity of an impending eruption if the width (or opening) of an ascending feeder dike is monitored in real-time through measurements of ground deformation and seismicity induced by the dike

    Magnesium substitution in calcium and strontium fluoro-phospho-aluminosilicate glasses by multinuclear 19F, 31P, 27Al, and 29Si MAS-NMR spectroscopy

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    Department of Trade and Industry, UK, under the project number of TP/5/REG/6/I/H0669

    Effects of ethyl-esterization, chain-lengths, unsaturation degrees, and hyperthermia on carcinostatic effect of omega-hydroxylated fatty acids

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    Aim: To evaluate promotive effect of hyperthermia on the carcinostatic activity of synthesized omega-hydroxy fatty acids (wHFAs) and their ethylesters agaist Ehrlich ascites tumor (EAT) cells. Methods: EAT cells were cultured with either wHFAs or their ethylester derivatives in a water bath at either 37 Β°C or 42 Β°C for 30 min, followed by incubation in a CO2 incubator for 20 or 72 h. Mitochondrial dehydrogenase-based WST-1 assay and trypan blue dye exclusion assay were then conducted after incubation. Morphological changes were observed by scanning electron microscopy (SEM). Results: Omega-HFA having a saturated 16-carbon straight-chain (wH16:0) was the most carcinostatic (at 37 Β°C – viability level: 60.0%; at 42 Β°C – 49.6% (WST-1)) among saturated and unsaturated wHFAs with 12, 15 or 16 carbon atoms, when administrated to EAT cells at 100 Β΅M for 20 h. Carcinostatic activity was markedly enhanced by ethyl-esterization of saturated fatty acids, such as wH16:0 (at 37 Β°C – 42.3%; at 42 Β°C – 11.2% , ibid) and wH15:0 (at 37 Β°C – 74.6%; at 42 Β°C – 25.3% , ibid), and their unsaturated counterparts were extremely effective only in combination with hyperthermia. Prolongation of the incubation period to 72 h at the same concentration increased appreciably their carcinostatic effect (wH16:0 ethylesther: 1.3%; wH15:0 ethylesther: 8.0%). These values were also supported by dye exclusion assay. The carcinostatic activity enhanced more markedly by hyperthermia (1.2%; 2.1%, ibid). SEM shows that wH16:0 ethylester-exposed EAT cells underwent extensive injury, such as deformation of cell structure or disappearance of microvilli. Conclusions: wH16:0 ethylester possesses high carcinostatic activity in vitro in combination with hyperthermia and may be utilized as potent anticancer therapeutic agent.ЦСль: ΠΏΡ€ΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡ€ΠΎΠ²Π°Ρ‚ΡŒ ΡƒΡΠΈΠ»ΠΈΠ²Π°ΡŽΡ‰ΠΈΠΉ эффСкт Π³ΠΈΠΏΠ΅Ρ€Ρ‚Π΅Ρ€ΠΌΠΈΠΈ Π½Π° ΠΊΠ°Π½Ρ†Π΅Ρ€ΠΎΡΡ‚Π°Ρ‚ΠΈΡ‡Π΅ΡΠΊΡƒΡŽ Π°ΠΊΡ‚ΠΈΠ²Π½ΠΎΡΡ‚ΡŒ синтСзированных омСгагидроксилированных ΠΆΠΈΡ€Π½Ρ‹Ρ… кислот (HFAs) ΠΈ ΠΈΡ… этиловых эфиров ΠΏΠΎ ΠΎΡ‚Π½ΠΎΠ΅Π½ΠΈΡŽ ΠΊ ΠΊΠ»Π΅Ρ‚ΠΊΠ°ΠΌ асцитной ΠΎΠΏΡƒΡ…ΠΎΠ»ΠΈ Ρ€Π»ΠΈΡ…Π° (EAT). ΠœΠ΅Ρ‚ΠΎΠ΄Ρ‹: ΠΊΠ»Π΅Ρ‚ΠΊΠΈ EAT ΠΈΠ½ΠΊΡƒΠ±ΠΈΡ€ΠΎΠ²Π°Π»ΠΈ с HFAs ΠΈΠ»ΠΈ ΠΈΡ… этилэфирными ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π½Ρ‹ΠΌΠΈ Π½Π° Π²ΠΎΠ΄Π½ΠΎΠΉ Π°Π½Π΅ ΠΏΡ€ΠΈ 37 Β° ΠΈΠ»ΠΈ 42 Β° Π² Ρ‚Π΅Ρ‡Π΅Π½ΠΈΠ΅ 30 ΠΌΠΈΠ½ с дальнСйим ΠΊΡƒΠ»ΡŒΡ‚ΠΈΠ²ΠΈΡ€ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ Π² 2 ΠΈΠ½ΠΊΡƒΠ±Π°Ρ‚ΠΎΡ€Π΅ Π½Π° протяТСнии 20 ΠΈΠ»ΠΈ 72 Ρ‡, послС Ρ‡Π΅Π³ΠΎ Π°Π½Π°Π»ΠΈΠ·ΠΈΡ€ΠΎΠ²Π°Π»ΠΈ ΠΆΠΈΠ·Π½Π΅ΡΠΏΠΎΡΠΎΠ±Π½ΠΎΡΡ‚ΡŒ ΠΊΠ»Π΅Ρ‚ΠΎΠΊ ΠΌΠ΅Ρ‚ΠΎΠ΄Π°ΠΌΠΈ Π°Π½Π°Π»ΠΈΠ·Π° WST-1, основанного Π½Π° активности ΠΌΠΈΡ‚ΠΎΡ…ΠΎΠ½Π΄Ρ€ΠΈΠ°Π»ΡŒΠ½Ρ‹Ρ… Π΄Π΅Π³ΠΈΠ΄Ρ€ΠΎΠ³Π΅Π½Π°Π·, ΠΈ ΠΏΠΎ Π²ΠΊΠ»ΡŽΡ‡Π΅Π½ΠΈΡŽ Ρ‚Ρ€ΠΈΠΏΠ°Π½ΠΎΠ²ΠΎΠ³ΠΎ синСго. ΠœΠΎΡ€Ρ„ΠΎΠ»ΠΎΠ³ΠΈΡ‡Π΅ΡΠΊΠΈΠ΅ измСнСния ΠΊΠ»Π΅Ρ‚ΠΎΠΊ опрСдСляли с использованиСм ΡΠΊΠ°Π½ΠΈΡ€ΡƒΡŽΡ‰Π΅ΠΉ элСктронной микроскопии. Π Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹: ΠΏΡ€ΠΈ ΠΊΡƒΠ»ΡŒΡ‚ΠΈΠ²Π°Ρ†ΠΈΠΈ ΠΊΠ»Π΅Ρ‚ΠΎΠΊ EAT Π² присутствии 100 M соСдинСний Π² Ρ‚Π΅Ρ‡Π΅Π½ΠΈΠ΅ 20 Ρ‡ ΠΎΠΌΠ΅Π³Π°-HFA с насыщСнной 16-ΡƒΠ³Π»Π΅Ρ€ΠΎΠ΄Π½ΠΎΠΉ прямой Ρ†Π΅ΠΏΡŒΡŽ (H16:0) проявляли Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ Π²Ρ‹Ρ€Π°ΠΆΠ΅Π½Π½Ρ‹ΠΉ канцСростатичСский эффСкт (ΠΏΡ€ΠΈ 37 Β° ΡƒΡ€ΠΎΠ²Π΅Π½ΡŒ ТизнСспосоности составил 60,0%; ΠΏΡ€ΠΈ 42 Β° 49,6% (WST-1)) ΠΏΠΎ ΡΡ€Π°Π²Π½Π΅Π½ΠΈΡŽ с Ρ‚Π°ΠΊΠΎΠ²Ρ‹ΠΌ насыщСнных ΠΈ нСнасыщСнных HFAs, содСрТащих 12, 15 ΠΈΠ»ΠΈ 16 Π°Ρ‚ΠΎΠΌΠΎΠ² ΡƒΠ³Π»Π΅Ρ€ΠΎΠ΄Π°. анцСростатичСская Π°ΠΊΡ‚ΠΈΠ²Π½ΠΎΡΡ‚ΡŒ Π·Π½Π°Ρ‡ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎ возрастала ΠΏΡ€ΠΈ этилэтСрификации насыщСнных ΠΆΠΈΡ€Π½Ρ‹Ρ… кислот, Ρ‚Π°ΠΊΠΈΡ… ΠΊΠ°ΠΊ H16:0 (ΠΏΡ€ΠΈ 37 Β° 42,3%; ΠΏΡ€ΠΈ 42 Β° 11,2%, ibid) ΠΈ H15:0 (ΠΏΡ€ΠΈ 37 Β° 74,6%; ΠΏΡ€ΠΈ 42 Β° 25,3% , ibid), Π² Ρ‚ΠΎ врСмя ΠΊΠ°ΠΊ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π½Ρ‹Π΅ нСнасыщСнных кислот Π±Ρ‹Π»ΠΈ высокоэффСктивны Ρ‚ΠΎΠ»ΡŒΠΊΠΎ Π² ΠΊΠΎΠΌΠ±ΠΈΠ½Π°Ρ†ΠΈΠΈ с Π³ΠΈΠΏΠ΅Ρ€Ρ‚Π΅Ρ€ΠΌΠΈΠ΅ΠΉ. Π£Π²Π΅Π»ΠΈΡ‡Π΅Π½ΠΈΠ΅ ΠΏΠ΅Ρ€ΠΈΠΎΠ΄Π° ΠΈΠ½ΠΊΡƒΠ±Π°Ρ†ΠΈΠΈ ΠΊΠ»Π΅Ρ‚ΠΎΠΊ Π΄ΠΎ 72 Ρ‡ ΠΏΡ€ΠΈ Ρ‚ΠΎΠΉ ΠΆΠ΅ ΠΊΠΎΠ½Ρ†Π΅Π½Ρ‚Ρ€Π°Ρ†ΠΈΠΈ вСщСств ΠΏΡ€ΠΈΠ²ΠΎΠ΄ΠΈΠ»ΠΎ ΠΊ Π·Π½Π°Ρ‡ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΠΌΡƒ ΡƒΠ²Π΅Π»ΠΈΡ‡Π΅Π½ΠΈΡŽ ΠΈΡ… канцСростатичСского дСйствия (этиловый эфир H16:0 1,3%; этиловый эфир H15:0 ethylesther 8,0%), ΠΏΠΎΠ΄Ρ‚Π²Π΅Ρ€ΠΆΠ΄Π΅Π½Π½ΠΎΠ³ΠΎ Π΄Π°Π½Π½Ρ‹ΠΌΠΈ окраски Ρ‚Ρ€ΠΈΠΏΠ°Π½ΠΎΠ²Ρ‹ΠΌ синим. Ρ€ΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ Π³ΠΈΠΏΠ΅Ρ€Ρ‚Π΅Ρ€ΠΌΠΈΠΈ Ρ‚Π°ΠΊΠΆΠ΅ усиливало канцСростатичСскоС дСйствиС соСдинСний (1,2%; 2,1%, ibid). Π Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹ исслСдования ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΎΠΌ SEM ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΈ, Ρ‡Ρ‚ΠΎ ΠΊΠ»Π΅Ρ‚ΠΊΠΈ EAT, ΠΈΠ½ΠΊΡƒΠ±ΠΈΡ€ΠΎΠ²Π°Π½Π½Ρ‹Π΅ с этиловым эфиром H16:0, Ρ€Π°Π·Ρ€ΡƒΠ°ΡŽΡ‚ΡΡ с Π½Π°Ρ€ΡƒΡˆΠ΅Π½ΠΈΠ΅ΠΌ ΠΊΠ»Π΅Ρ‚ΠΎΡ‡Π½ΠΎΠΉ структуры ΠΈ исчСзновСниСм ΠΌΠΈΠΊΡ€ΠΎΠ²ΠΎΠ»ΠΎΠΊΠΎΠ½. Π’Ρ‹Π²ΠΎΠ΄Ρ‹: Π² ΠΊΠΎΠΌΠ±ΠΈΠ½Π°Ρ†ΠΈΠΈ с Π³ΠΈΠΏΠ΅Ρ€Ρ‚Π΅Ρ€ΠΌΠΈΠ΅ΠΉ этиловый эфир H16:0 ΠΏΡ€ΠΎ Π΅Ρ‚ Π²Ρ‹ΡΠΎΠΊΡƒΡŽ ΠΊΠ°Π½Ρ†Π΅Ρ€ΠΎΡΡ‚Π°Ρ‚ΠΈΡ‡Π΅ΡΠΊΡƒΡŽ Π°ΠΊΡ‚ΠΈΠ²Π½ΠΎΡΡ‚ΡŒ in vitro, Ρ‡Ρ‚ΠΎ Π³ΠΎΠ²ΠΎΡ€ΠΈΡ‚ ΠΎ возмоТности примСнСния соСдинСния Π² Ρ‚Π΅Ρ€Π°ΠΏΠΈΠΈ ΠΎΠΏΡƒΡ…ΠΎΠ»Π΅Π²Ρ‹Ρ… Π·Π°Π±ΠΎΠ»Π΅Π²Π°Π½ΠΈΠΉ

    Spatially explicit approach to estimation of total population abundance in field surveys.

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    Population abundance is fundamental in ecology and conservation biology, and provides essential information for predicting population dynamics and implementing conservation actions. While a range of approaches have been proposed to estimate population abundance based on existing data, data deficiency is ubiquitous. When information is deficient, a population estimation will rely on labor intensive field surveys. Typically, time is one of the critical constraints in conservation, and management decisions must often be made quickly under a data deficient situation. Hence, it is important to acquire a theoretical justification for survey methods to meet a required estimation precision. There is no such theory available in a spatially explicit context, while spatial considerations are critical to any field survey. Here, we develop a spatially explicit theory for population estimation that allows us to examine the estimation precision under different survey designs and individual distribution patterns (e.g. random/clustered sampling and individual distribution). We demonstrate that clustered sampling decreases the estimation precision when individuals form clusters, while sampling designs do not affect the estimation accuracy when individuals are distributed randomly. Regardless of individual distribution, the estimation precision becomes higher with increasing total population abundance and the sampled fraction. These insights provide theoretical bases for efficient field survey designs in information deficiency situations

    Measurement of the cosmic-ray antiproton spectrum at solar minimum with a long-duration balloon flight over Antarctica

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    The energy spectrum of cosmic-ray antiprotons from 0.17 to 3.5 GeV has been measured using 7886 antiprotons detected by BESS-Polar II during a long-duration flight over Antarctica near solar minimum in December 2007 and January 2008. This shows good consistency with secondary antiproton calculations. Cosmologically primary antiprotons have been investigated by comparing measured and calculated antiproton spectra. BESS-Polar II data show no evidence of primary antiprotons from evaporation of primordial black holes.Comment: 4 pages, 4 figures, submitted to Physical Review Letter

    Measurement of Cosmic-Ray Antiproton Spectrum at Solar Minimum with a Long-Duration Balloon Flight in Antarctica

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    The energy spectrum of cosmic-ray antiprotons (p(raised bar)'s) collected by the BESS-Polar II instrument during a long-duration flight over Antarctica in the solar minimum period of December 2007 through January 2008. The p(raised bar) spectrum measured by BESS-Polar II shows good consistency with secondary p(raised bar) calculations. Cosmologically primary p(raised bar)'s have been searched for by comparing the observed and calculated p(raised bar) spectra. The BESSPolar II result shows no evidence of primary p(raised bar)'s originating from the evaporation of PBH

    Aggregatibacter actinomycetemcomitans Omp29 Is Associated with Bacterial Entry to Gingival Epithelial Cells by F-Actin Rearrangement

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    The onset and progressive pathogenesis of periodontal disease is thought to be initiated by the entry of Aggregatibacter actinomycetemcomitans (Aa) into periodontal tissue, especially gingival epithelium. Nonetheless, the mechanism underlying such bacterial entry remains to be clarified. Therefore, this study aimed to investigate the possible role of Aa outer membrane protein 29 kD (Omp29), a homologue of E. coli OmpA, in promoting bacterial entry into gingival epithelial cells. To accomplish this, Omp29 expression vector was incorporated in an OmpA-deficient mutant of E. coli. Omp29+/OmpAβˆ’ E. coli demonstrated 22-fold higher entry into human gingival epithelial line cells (OBA9) than Omp29βˆ’/OmpAβˆ’ E. coli. While the entry of Aa and Omp29+/OmpAβˆ’ E. coli into OBA9 cells were inhibited by anti-Omp29 antibody, their adherence to OBA9 cells was not inhibited. Stimulation of OBA9 cells with purified Omp29 increased the phosphorylation of focal adhesion kinase (FAK), a pivotal cell-signaling molecule that can up-regulate actin rearrangement. Furthermore, Omp29 increased the formation of F-actin in OBA9 cells. The internalization of Omp29-coated beads and the entry of Aa into OBA9 were partially inhibited by treatment with PI3-kinase inhibitor (Wortmannin) and Rho GTPases inhibitor (EDIN), both known to convey FAK-signaling to actin-rearrangement. These results suggest that Omp29 is associated with the entry of Aa into gingival epithelial cells by up-regulating F-actin rearrangement via the FAK signaling pathway

    Precise measurements of hydrogen and helium isotopes with BESS-Polar II

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    A precise knowledge of cosmic-ray hydrogen and helium isotopes provides important information to better understand Galactic cosmic-ray propagation. Deuteron and helium 3 species are mainly secondary particles created by the spallation of primary proton and helium 4 particles during their propagation in the Galaxy. Secondary-to-primary ratios thus bring direct information on the average amount of material traversed by cosmic rays in the interstellar medium. The Balloon-borne Experiment with Superconducting Spectrometer BESS-Polar II flew over Antarctica for 24.5 days from December 2007 through January 2008, during the 23rd solar cycle minimum. The instrument is made of complementary particle detectors which allow to precisely measure the charge, velocity and rigidity of incident cosmic rays. It can accurately separate and precisely measure cosmic-ray hydrogen and helium isotopes between 0.2 and 1.5 GeV/nucleon. These data, which are the most precise to date, will be reported and their implications will be discussed
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