36 research outputs found

    Oxidation and Release of Ruthenium from White Inclusions

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    In this paper the laboratory test results on oxidation and release of ruthenium as a fission product element are summarised. The ruthenium appears in the nuclear fuel pellets of pressurized water reactors as one of the fission product elements during burnup. In case of severe accident when the air can contact the degraded hot fuel, the ruthenium oxidises and its gaseous oxides, especially the RuO4, release rapidly from the pellets to the environment. Because of high radio- and chemotoxicity of ruthenium tetra-oxide further experimental study of oxidation and release is essential. It is well known that ruthenium in the irradiated fuel UO2 fuel appears in small metallic alloy precipitations together with fission product elements as Mo, Rh, Pd and Tc. The precipitations are seen in the metallographic pictures as white inclusions. This separate effect study focused on the differences in the release rate of gaseous ruthenium oxides when pure ruthenium or Mo-Ru-Rh-Pd metallic alloy is present in the simulated nuclear fuel. The oxidation and release were studied at constant reaction temperatures of 1000 or 1100 Celsius. The tests showed that during high-temperature oxidation of the Mo-Ru-Rh-Pd alloy in air flow the release rate of gaseous ruthenium oxides is reduced to 60-80% compared to the value measured in case of oxidation of pure metallic ruthenium powder in the same thermal-hydraulic conditions. Furthermore, if additional elements and chemical compounds representing other fission products were added in the alloy, a time delay of 30 to 60 min appeared in the release of gaseous ruthenium to the room-temperature environment. One of the main results was that in the outlet air flow reaching the environment the partial pressure of RuO4 was far above what could be expected for room-temperature equilibrium conditions. It was pointed out that the highly volatile RuO4 can decompose in solid, non-volatile RuO2 and O2. The X-ray fluorescence analysis results showed that some ruthenium compounds deposited on the colder circuit walls of the test facility. This suggests RuO4 is not fully airstable, i.e., its stability in air can be limited in time.JRC.F.4-Nuclear design safet

    Methods for identifying high-redshift galaxy cluster candidates

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    Recent theories linked long gamma ray bursts (GRBs) to galaxies with rapid star formation or starburst; thus, we expect that long GRBs (LGRBs) are more frequent in midcluster galaxies where mergers and tidal interactions between gas-rich galaxies are more likely to occur. Yet there is no galaxy cluster known to be associated with LGRBs. We demonstrate that, based on deep, single-band Subaru Hyper Suprime-Cam observations, we may provide constraints on photometric redshifts of groups of galaxies. We compare three methods: cosmological approach, pseudoinverse matrix, and random forests to estimate galaxy and quasar redshifts. Comparing our results to spectroscopic redshifts of Sloan Digital Sky Survey's-detected extragalactic sources, random forests may provide the highest accuracy with as low as 17 percentage error. This is a powerful method to find clusters to place GRB host galaxies in their local environment

    Environmental properties of cells improve machine learning-based phenotype recognition accuracy

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    To answer major questions of cell biology, it is often essential to understand the complex phenotypic composition of cellular systems precisely. Modern automated microscopes produce vast amounts of images routinely, making manual analysis nearly impossible. Due to their efficiency, machine learningbased analysis software have become essential tools to perform single-cell-level phenotypic analysis of large imaging datasets. However, an important limitation of such methods is that they do not use the information gained from the cellular micro-and macroenvironment: the algorithmic decision is based solely on the local properties of the cell of interest. Here, we present how various features from the surrounding environment contribute to identifying a cell and how such additional information can improve single-cell-level phenotypic image analysis. The proposed methodology was tested for different sizes of Euclidean and nearest neighbour-based cellular environments both on tissue sections and cell cultures. Our experimental data verify that the surrounding area of a cell largely determines its entity. This effect was found to be especially strong for established tissues, while it was somewhat weaker in the case of cell cultures. Our analysis shows that combining local cellular features with the properties of the cell's neighbourhood significantly improves the accuracy of machine learning-based phenotyping.Peer reviewe

    Catches of Euxoa tritici in pheromone traps for Anarsia lineatella are due to the presence of (Z)-5-decenyl acetate as an impurity

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    Traps baited with the synthetic pheromone of Anarsia lineatella Zeller (Lepidoptera: Gelechiidae) frequently captured also Euxoa tritici L. males (Lepidoptera: Noctuidae) in field tests in Hungary. As (E)-monounsaturated compounds are uncommon among sex attractants or pheromone components of Noctuidae, it was hypothesized that the Euxoa catches may have been due to impurities of the (Z) isomer in synthetic (E)-5-decenyl acetate, which is the major component in the pheromone lure of A. lineatella. Traps baited with synthetic (Z)-5-decenyl acetate captured large numbers of E. tritici, and the compound showed a clear dose-response effect. Reanalysis of the synthetic batch of (E)-5-decenyl acetate used in preparation of the A. lineatella lure showed the presence of 10% of the (Z) isomer. Traps baited with synthetic (Z)-5-decenyl acetate can be used in the future for detection and monitoring purposes of E. tritici, a widely distributed pest of cereals and other field crops. The compound also showed attraction of Euxoa seliginis Duponchel

    Galactic foreground of gamma-ray bursts from AKARI Far-Infrared Surveyor

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    We demonstrate the use of the AKARI FIS All-Sky Survey maps in the study of extragalactic objects. A quick but reliable estimate of the Galactic foreground is essential for extragalactic research in general. We explored the galactic foreground and calculated hydrogen column densities using AKARI FIS and other recent all-sky survey data, and compared our results to former estimates. Our AKARI-FIS-based foreground values were then used toward gamma-ray burst (GRB) sources as input for X-ray afterglow spectrum fitting. From those fits the intrinsic column densities at the GRB sources were derived. The high-angular-resolution AKARI-FIS-based Galactic foreground hydrogen column densities are statistically very similar, but for most of the tested directions somewhat lower than previous estimates based on low-resolution data. This is due to the low filling factor of high-density enhancements in all galactic latitudes. Accordingly, our AKARI-FIS-based new intrinsic hydrogen column densities are usually higher or similar compared to the values calculated based, e.g., on the low-resolution Leiden/Argentine/Bonn survey data and listed in the Leicester database. The variation, however, is typically smaller than the error of the estimate from the fits of the X-ray afterglow spectra. There are a number of directions where the improvement of the foreground estimates resulted in an overestimate of magnitude or higher increment of the derived intrinsic hydrogen column densities. We concluded that most of the GRBs with formerly extremely low intrinsic hydrogen column densities are in fact normal, but we confirmed that GRB050233 is indeed a non- enveloped long GRB

    Agri-food business: Global challenges â Innovative solutions

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    The rise of a western-style middle class in many successful emerging economies like China currently is inducing deep structural changes on agricultural world markets and within the global agri-food business. As a result of both higher incomes and concerns over product safety and quality the global demand for high-quality and safe food products is increasing significantly. In order to meet the new required quality, globally minimum quality standards are rising and private standards emerging. All over the world these developments cause adjustments at the enterprise, chain and market levels. At the same time, the tremendously increasing demand for renewable energy has led to the emergence of a highly promising market for biomass production. This has far-reaching consequences for resource allocation in the agri-food business, for the environment, for the poor in developing countries and for agricultural policy reforms. The challenges increase with ongoing liberalisation, globalisation and standardisation, all of which change trade patterns for agricultural and food commodities, and influence production costs and commodity prices. The objective of the IAMO Forum is to show opportunities as well as risks for all participants of the food economy in the ongoing globalisation process: for small peasants in developing countries, farmers in Europe and globally active food enterprises and retailers. The success of enterprises depends on the ability to find innovative solutions with regard to the organisation of enterprises, chains, and markets, as well as future policy design. Concerning bio-energy strategies has to be identified to combat global warming most efficiently and concurrently attenuate the competition between "tank and table" on farmland. IAMO Forum 2008, as well as this book, would not have been possible without the engagement of many people and institutions. We thank the authors of the papers, as well as the referees. Furthermore we are highly indebted to MARLIES LOHR, NADINE GIEMSA and RONNY RECKE who in an outstanding way contributed to the organisation of the Forum. This is true as well for the IAMO administration, whose work we gratefully acknowledge. Many sponsors has funded the IAMO Forum 2008. We are very grateful to the German Research Foundation (DFG), The Federal Ministry of Food, Agriculture and Consumer Production in Germany, The Ministry of Cultural Affairs of the Federal State Saxony-Anhalt, Germany and last but not least the City of Halle. Further Conference sponsors are the BIONADE Corporation, Gaensefurther Mineral Water, The Wine Growers Association of the Region Saale-Unstrut, Germany, Obsthof am SüÃen See GmbH, Monsanto Company, KWS Saat AG, Sachsen-Anhalt-Tours, Baumkuchen Salzwedel and the Hallesches Brauhaus.Agribusiness, Agricultural and Food Policy, Agricultural Finance, Community/Rural/Urban Development, Industrial Organization, Institutional and Behavioral Economics, International Development, Marketing, Political Economy,

    Endoscopic sphincterotomy for delaying choLecystectomy in mild acute biliarY pancreatitis (EMILY study): Protocol of a multicentre randomised clinical trial

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    Introduction: According to the literature, early cholecystectomy is necessary to avoid complications related to gallstones after an initial episode of acute biliary pancreatitis (ABP). A randomised, controlled multicentre trial (the PONCHO trial) revealed that in the case of gallstone-induced pancreatitis, early cholecystectomy was safe in patients with mild gallstone pancreatitis and reduced the risk of recurrent gallstone-related complications, as compared with interval cholecystectomy. We hypothesise that carrying out a sphincterotomy (ES) allows us to delay cholecystectomy, thus making it logistically easier to perform and potentially increasing the efficacy and safety of the procedure. Methods/Design: EMILY is a prospective, randomised, controlled multicentre trial. All patients with mild ABP, who underwent ES during the index admission or in the medical history will be informed to take part in EMILY study. The patients will be randomised into two groups: (1) early cholecystectomy (within 6 days after discharge) and (2) patients with delayed (interval) cholecystectomy (between 45 and 60 days after discharge). During a 12-month period, 93 patients will be enrolled from participating clinics. The primary endpoint is a composite endpoint of mortality and recurrent acute biliary events (that is, recurrent ABP, acute cholecystitis, uncomplicated biliary colic and cholangitis). The secondary endpoints are organ failure, biliary leakage, technical difficulty of the cholecystectomy, surgical and other complications

    Human keratinocytes are vanilloid resistant

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    BACKGROUND: Use of capsaicin or resiniferatoxin (RTX) as analgesics is an attractive therapeutic option. RTX opens the cation channel inflammatory pain/vanilloid receptor type 1 (TRPV1) permanently and selectively removes nociceptive neurons by Ca(2+)-cytotoxicity. Paradoxically, not only nociceptors, but non-neuronal cells, including keratinocytes express full length TRPV1 mRNA, while patient dogs and experimental animals that underwent topical treatment or anatomically targeted molecular surgery have shown neither obvious behavioral, nor pathological side effects. METHODS: To address this paradox, we assessed the vanilloid sensitivity of the HaCaT human keratinocyte cell line and primary keratinocytes from skin biopsies. RESULTS: Although both cell types express TRPV1 mRNA, neither responded to vanilloids with Ca(2+)-cytotoxicity. Only ectopic overproduction of TRPV1 rendered HaCaT cells sensitive to low doses (1-50 nM) of vanilloids. The TRPV1-mediated and non-receptor specific Ca(2+)-cytotoxicity ([RTX]>15 microM) could clearly be distinguished, thus keratinocytes were indeed resistant to vanilloid-induced, TRPV1-mediated Ca(2+)-entry. Having a wider therapeutic window than capsaicin, RTX was effective in subnanomolar range, but even micromolar concentrations could not kill human keratinocytes. Keratinocytes showed orders of magnitudes lower TRPV1 mRNA level than sensory ganglions, the bona fide therapeutic targets in human pain management. In addition to TRPV1, TRPV1b, a dominant negative splice variant was also noted in keratinocytes. CONCLUSION: TRPV1B expression, together with low TRPV1 expression, may explain the vanilloid paradox: even genuinely TRPV1 mRNA positive cells can be spared with therapeutic (up to micromolar) doses of RTX. This additional safety information might be useful for planning future human clinical trials
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