2,358 research outputs found

    Multiwavelength observations of a bright impact flash during the January 2019 total lunar eclipse

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    We discuss here a lunar impact flash recorded during the total lunar eclipse that occurred on 2019 January 21, at 4h 41m 38.09 +- 0.01 s UT. This is the first time ever that an impact flash is unambiguously recorded during a lunar eclipse and discussed in the scientific literature, and the first time that lunar impact flash observations in more than two wavelengths are reported. The impact event was observed by different instruments in the framework of the MIDAS survey. It was also spotted by casual observers that were taking images of the eclipse. The flash lasted 0.28 seconds and its peak luminosity in visible band was equivalent to the brightness of a mag. 4.2 star. The projectile hit the Moon at the coordinates 29.2 +- 0.3 ∘^{\circ}S, 67.5 +- 0.4 ∘^{\circ}W. In this work we have investigated the most likely source of the projectile, and the diameter of the new crater generated by the collision has been calculated. In addition, the temperature of the lunar impact flash is derived from the multiwavelength observations. These indicate that the blackbody temperature of this flash was of about 5700 K.Comment: Accepted for publication in MNRAS on 2019 March 2

    Influence of the new immunosuppressive combinations on arterial hypertension after renal transplantation

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    Influence of the new immunosuppressive combinations on arterial hypertension after renal transplantation. Arterial hypertension is highly prevalent after renal transplantation and may contribute to the risk of cardiovascular disease. Also, arterial hypertension has been reported to be an independent risk factor for graft failure. Immunosuppressive drugs such as corticosteroids, cyclosporine and tacrolimus may be important contributing factors to post-transplant hypertension. Recent data from multicenter trials and from conversion studies (cyclosporine to tacrolimus) suggest that renal transplant patients under tacrolimus-based therapy showed less arterial hypertension compared with cyclosporine treated patients. New immunosuppressive drugs, including mycophenolate mofetil and rapamycin, are not nephrotoxic and they do not have any hypertensive effect. New immunosuppressive combinations including mycophenolate mofetil in a triple therapy regimen (associated with corticosteroids and cyclosporine) can reduce blood pressure so that corticosteroids can be stopped or cyclosporine reduced or even eliminated. Non-nephrotoxic regimens using rapamycin (sirolimus) as basic immunosuppression, associated with azathioprine or mycophenolate mofetil, could reduce the incidence of post-transplant arterial hypertension. Also, in renal transplant patients initially immunosuppressed with rapamycin, cyclosporine and corticosteroids, after the elimination of CSA, a lower blood pressure is achieved. In summary, new protocols with mycophenolate mofetil and/or rapamycin may permit several combinations that offer important alternatives to classical immunosuppressive regimens to reduce the incidence and clinical impact of arterial hypertension after renal transplantation

    Laser Shock Microformingof Thin Metal Sheets with ns Lasers

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    Continuous and long-pulse lasers have been used for the forming of metal sheets in macroscopic mechanical applications. However, for the manufacturing of micro-electromechanical systems (MEMS), the use of ns laser pulses provides a suitable parameter matching over an important range of sheet components that, preserving the short interaction time scale required for the predominantly mechanical (shock) induction of deformation residual stresses, allows for the successful processing of components in a medium range of miniaturization without appreciable thermal deformation.. In the present paper, the physics of laser shock microforming and the influence of the different experimental parameters on the net bending angle are presented

    GNUsmail: Open framework for on-line email classification

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    Real-time classification of massive email data is a challenging task that presents its own particular difficulties. Since email data presents an important temporal component, several problems arise: emails arrive continuously, and the criteria used to classify those emails can change, so the learning algorithms have to be able to deal with concept drift. Our problem is more general than spam detection, which has received much more attention in the literature. In this paper we present GNUsmail, an open-source extensible framework for email classification, which structure supports incremental and on-line learning. This framework enables the incorporation of algorithms developed by other researchers, such as those included in WEKA and MOA. We evaluate this framework, characterized by two overlapping phases (pre-processing and learning), using the ENRON dataset, and we compare the results achieved by WEKA and MOA algorithms

    Analysis of Moon impact flashes detected during the 2012 and 2013 Perseids

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    We present the results of our Moon impact flashes detection campaigns performed around the maximum activity period of the Perseid meteor shower in 2012 and 2013. Just one flash produced by a Perseid meteoroid was detected in 2012 because of very unfavourable geometric conditions, but 12 of these were confirmed in 2013. The visual magnitude of the flashes ranged between 6.6 and 9.3. A luminous efficiency of 1.8 ×\times 10−3^{-3} has been estimated for meteoroids from this stream. According to this value, impactor masses would range between 1.9 and 190 g. In addition, we propose a criterion to establish, from a statistical point of view, the likely origin of impact flashes recorded on the lunar surface.Comment: Accepted for publication in Astronomy and Astrophysics on March 11, 201

    Impact assessment of mechanical harvest on fruit physiology and consequences on oil physicochemical and sensory quality from ‘Manzanilla de Sevilla’ and ‘Manzanilla Cacereña’ super-high-density hedgerows. A preliminary study

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    BACKGROUND Super-intensive cultivation facilitates olive mechanized harvesting, allowing substantial savings in the production cost of virgin olive oil (VOO). However, the number of varieties adapted to this type of cultivation is small. This study explores the impact that harvesting with a grape straddle harvester of ‘Manzanilla de Sevilla’ and ‘Manzanilla Cacereña’ olives grown in super-intensive cultivation has on the physiology of the fruit and the quality of the oil subsequently extracted. RESULTS For both cultivars, fruits harvested mechanically showed higher respiration and ethylene production and lower firmness than fruits harvested by hand. Their oils exhibited lower phenol contents, lower oxidative stability and lower presence of positive sensory attributes. However, in these oils the values of parameters used to assess the level of quality of VOO remained within the limits required for the best commercial category. CONCLUSION Mechanical harvesting of ‘Manzanilla de Sevilla’ and ‘Manzanilla Cacereña’ super-high-density hedgerows induced physiological alterations in the fruits and a reduction in the contents of natural antioxidants and flavour components in the oils, though it did not result in a loss of the ‘Extra’ level of quality. © 2014 Society of Chemical IndustryThis work was funded by the research project AGL2011-30371-C02-02 of the Spanish State Secretary for Research and by the FEDER program. Special thanks are due to Elaia SA for providing facilities for this study and to Alejandro Trigo (technical assistant of Elaia SA), MarĂ­a del Carmen MartĂ­nez, Cristina RodrĂ­guez and Antonio Montero for technical assistance.Peer Reviewe
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