1,015 research outputs found

    Применение метода долгосрочного прогнозирования водонефтяного фактора для определения максимально возможного расчётного объёма добычи нефти месторождения "Чёрный Дракон", Вьетнам

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    Objective - Although junctional adhesion molecule-A (JAM-A) has recently been implicated in leukocyte recruitment on early atherosclerotic endothelium and after reperfusion injury, its role in neointima formation after arterial injury remains to be elucidated. Methods and Results - Here we show that the genetic deletion of JAM-A in apolipoprotein E - deficient (apoE(-/-)) mice significantly reduced neointimal hyperplasia after wire injury of carotid arteries without altering medial area. This was associated with a significant decrease in neointimal macrophage content, whereas the relative content of smooth muscle cells and endothelial recovery was unaltered in JAM-A(-/-) apoE(-/-) compared with JAM-A(-/-) apoE(-/-) lesions. In carotid arteries perfused ex vivo, deficiency in JAM-A significantly impaired the recruitment of monocytes 1 week, but not 1 day, after injury. These effects were paralleled by an attenuation of monocyte arrest and transmigration on activated JAM-A(-/-) apoE(-/-) versus JAM-A(-/-) apoE(-/-) endothelial cells under flow conditions in vitro. A mechanism underlying reduced recruitment was implied by findings that the luminal expression of the arrest chemokine RANTES in injured arteries and its endothelial deposition by activated platelets in vitro were diminished by JAM-A deficiency. Conclusions - Our data provide the first evidence to our knowledge for a crucial role of JAM-A in accelerated lesion formation and monocyte infiltration in atherosclerosis-prone mice

    Statistical Survey of Type III Radio Bursts at Long Wavelengths Observed by the Solar TErrestrial RElations Observatory (STEREO)/Waves Instruments: Radio Flux Density Variations with Frequency

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    We have performed a statistical study of 152152 Type III radio bursts observed by Solar TErrestrial RElations Observatory (STEREO)/Waves between May 2007 and February 2013. We have investigated the flux density between 125125kHz and 1616MHz. Both high- and low-frequency cutoffs have been observed in 6060\,% of events suggesting an important role of propagation. As already reported by previous authors, we observed that the maximum flux density occurs at 11MHz on both spacecraft. We have developed a simplified analytical model of the flux density as a function of radial distance and compared it to the STEREO/Waves data.Comment: published in Solar Physic

    Isotopic and spin selectivity of H_2 adsorbed in bundles of carbon nanotubes

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    Due to its large surface area and strongly attractive potential, a bundle of carbon nanotubes is an ideal substrate material for gas storage. In addition, adsorption in nanotubes can be exploited in order to separate the components of a mixture. In this paper, we investigate the preferential adsorption of D_2 versus H_2(isotope selectivity) and of ortho versus para(spin selectivity) molecules confined in the one-dimensional grooves and interstitial channels of carbon nanotube bundles. We perform selectivity calculations in the low coverage regime, neglecting interactions between adsorbate molecules. We find substantial spin selectivity for a range of temperatures up to 100 K, and even greater isotope selectivity for an extended range of temperatures,up to 300 K. This isotope selectivity is consistent with recent experimental data, which exhibit a large difference between the isosteric heats of D_2 and H_2 adsorbed in these bundles.Comment: Paper submitted to Phys.Rev. B; 17 pages, 2 tables, 6 figure

    Filling a blank on the map: 60 years of fisheries in Equatorial Guinea

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    Despite a scarcity of pertinent information, it has been possible to reconstruct time series of marine fisheries catches for Equatorial Guinea from 1950 to 2010 using per capita fish consumption and population numbers for small-scale fisheries, catch rates and number of vessels for industrial fisheries and discard rates to estimate the discarded bycatch. Small-scale fisheries, industrial large-scale fisheries, domestic and legal and illegal foreign fisheries and their discards are all included. Total catches were estimated at 2.7 million tonnes over the time period considered, of which 653 000 t were caught domestically compared to 187 000 t reported by FAO. This shows that fisheries have more importance for Equatorial Guinea's food security than the official data suggest. In contrast to what is suggested by official figures, fisheries were shown to be strongly impacted by civil and political unrest; notably, they declined overall because of civil and political conflicts, socio-demographic dynamics, and a growing role of the newly discovered oil resources, which directly and indirectly threaten the food security of the people of Equatorial Guinea

    Avaliação de adsorventes sólidos para determinação de pesticidas organoclorados e bifenilos policlorados na atmosfera marinha

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    A sampling system was developed to be used in coastal areas and on board of océanographie vessels for the determination of chlorinated pesticides and polychlorinated biphenyls (PCB) in the atmosphere. The basis of the system is the pre-concentration step on solid adsorbents. Florisil, XAD-2 resin and polyurethane foam (PUF) were tested. The sampling efficiency presented variations between 16-118% (florisil), 41131% (XAD-2) and 66-122% (PUF) depending on the organochlorine compound.Um sistema de amostragem foi desenvolvido para ser usado em áreas costeiras e a bordo de embarcações oceanográficas para a determinação de pesticidas organoclorados e bifenilos policlorados (PCBs) na atmosfera. Este sistema baseia-se na pré-concentração em adsorventes sólidos. Foram usados Florosil, Resina XAD-2 e espuma de poliuretano (EPU). A eficiência de amostragens para estes adsorventes foi de 16-118% (florosil), 41-131% (XAD-2) e 66-112 (EPU), para os compostos organoclorados analisados

    Search for an invisibly decaying Higgs boson in e^+e^- collisions at \sqrt{s} = 183 - 189 GeV

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    A search for a Higgs boson decaying into invisible particles is performed using the data collected at LEP by the L3 experiment at centre-of-mass energies of 183 GeV and 189 GeV. The integrated luminosities are respectively 55.3 pb^-1 and 176.4 pb^-1. The observed candidates are consistent with the expectations from Standard Model processes. In the hypothesis that the production cross section of this Higgs boson equals the Standard Model one and the branching ratio into invisible particles is 100%, a lower mass limit of 89.2 GeV is set at 95% confidence level

    Search for Extra Dimensions in Boson and Fermion Pair Production in e+e- Interactions at LEP

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    Extra spatial dimensions are proposed by recent theories that postulate the scale of gravity to be of the same order as the electroweak scale. A sizeable interaction between gravitons and Standard Model particles is then predicted. Effects of these new interactions in boson and fermion pair production are searched for in the data sample collected at centre-of-mass energies above the Z pole by the L3 detector at LEP. In addition, the direct production of a graviton associated with a Z boson is investigated. No statistically significant hints for the existence of these effects are found and lower limits in excess of 1 TeV are derived on the scale of this new theory of gravity

    Measurement of the Tau Branching Fractions into Leptons

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    Using data collected with the L3 detector near the Z resonance, corresponding to an integrated luminosity of 150pb-1, the branching fractions of the tau lepton into electron and muon are measured to be B(tau->e nu nu) = (17.806 +- 0.104 (stat.) +- 0.076 (syst.)) %, B(tau->mu nu nu) = (17.342 +- 0.110 (stat.) +- 0.067 (syst.)) %. From these results the ratio of the charged current coupling constants of the muon and the electron is determined to be g_mu/g_e = 1.0007 +- 0.0051. Assuming electron-muon universality, the Fermi constant is measured in tau lepton decays as G_F = (1.1616 +- 0.0058) 10^{-5} GeV^{-2}. Furthermore, the coupling constant of the strong interaction at the tau mass scale is obtained as alpha_s(m_tau^2) = 0.322 +- 0.009 (exp.) +- 0.015 (theory)

    Higgs Candidates in e+e- Interactions at root(s) = 206.6 GeV

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    In a search for the Standard Model Higgs boson, carried out on 212.5 pb-1 of data collected by the L3 detector at the highest LEP centre-of-mass energies, including 116.5 pb-1 above root(s) = 206GeV, an excess of candidates for the process e+e- -> Z* -> HZ is found for Higgs masses near 114.5GeV. We present an analysis of our data and the characteristics of our strongest candidates.Comment: Footnote added, matches the version to be published in Physics Letters
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