430 research outputs found

    The Size of the Narrow-Line Emitting Region in the Seyfert 1 Galaxy NGC 5548 from Emission-Line Variability

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    The narrow [O III] 4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow line-emitting region has a radius of only 1-3 pc and is denser (n ~ 10^5 cm^{-3}) than previously supposed. The [O III] line width is consistent with virial motions at this radius given previous determinations of the black hole mass.Since the [O III] emission-line flux is usually assumed to be constant and is therefore used to calibrate spectroscopic monitoring data, the variability has ramifications for the long-term secular variations of continuum and emission-line fluxes, though it has no effect on shorter-term reverberation studies. We present corrected optical continuum and broad Hbeta emission-line light curves for the period 1988 to 2008.Comment: 11 pages, 5 figures, 6 tables. Accepted for publication in Ap

    CLIMATIC VARIABILITY OF THE SOUTH PACIFIC OCEAN DURING 1900–2010 IN THE ENVIRONMENTAL RECORDS OF WEST ANTARCTICA

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    In this work, we present the climatic evolution of the South Pacific Ocean from 1900 to 2010 and its environmental influence over West Antarctica. We analyzed the sea surface temperature, mean sea level pressure, and meridional wind (at 850 hPa) of the South Pacific Ocean using ERA-20C reanalysis (European Center for Medium-Range Weather Forecasts) and compared these parameters with the regional temperature obtained indirectly (by proxy) from two ice cores from the West Antarctic ice sheet (Mount Johns and Ferrigno). The sea surface temperature increased in almost the entire South Pacific Ocean from 1900 to 2010; in the equatorial Pacific, it increased by 2.1 °C from 1916 to 1997, while in the middle latitudes of the South Pacific, it increased by 1.1 °C from 1923 to 2001. This increase occurred concurrently with a positive trend in the Southern Annular Mode and a change the mean sea level pressure anomaly from 1960 onwards. This atmospheric pressure increased at middle latitudes and decreased around Antarctica in the circumpolar low-pressure zone, strengthening the Amundsen Sea Low and changing the pattern of the meridional wind anomaly (at 850 hPa) between medium and high latitudes in the South Pacific. Furthermore, since 1960, a greater flow from north to south (onshore) has predominated from the southeast South Pacific to the north of West Antarctica. Such changes caused a reduction in the sea ice extent in the Amundsen and Bellingshausen Seas and an increase in average atmospheric temperature primarily in the coastal region of West Antarctica, as demonstrated by the Ferrigno ice core record. Conversely, the Mount Johns region did not show the same trend in atmospheric temperature, as it was influenced mainly by cold air masses from the Antarctic ice shee

    The Impact of Plasma Activated Water Treatment on the Phenolic Profile, Vitamins Content, Antioxidant and Enzymatic Activities of Rocket-Salad Leaves

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    Plasma activated water (PAW) recently received much attention as an alternative food preservation method. However, its effects on food quality are still scarce. This study evaluates the effect of PAW processing time on bioactive compounds of rocket-salad leaves including: 18 phenolic compounds, vitamin C, riboflavin, nicotinic acid, and nicotinamide. Moreover, the impact of PAW on both antioxidant (DPPH) and peroxidase (POD) activities was also investigated. This was performed using HPLC-DAD, HPLC-MS/MS, and spectrophotometric analysis. All treatments induced non-significant increases in total phenolic contents. However, depending on processing time, significant increases or decreases of individual phenolic compounds were observed. PAW-10 and -20 increased the ascorbic acid content to 382.76 and 363.14 mg/100 g, respectively, compared to control (337.73 mg/100 g). Riboflavin and nicotinic acid contents were increased significantly in PAW-20 (0.53 and 1.26 mg/100), compared to control (0.32 and 0.61 mg/100 g, respectively). However, nicotinamide showed non-significant increase in all treatments. Antioxidant activity improved significantly only in PAW-20, while peroxidase activity was reduced up to 36% in the longest treatment. In conclusion, PAW treatment could be an effective technique for rocket decontamination since it positively influenced the quality of rocket, improving the retention of polyphenols and vitamins

    Effect of plasma activated water (PAW) on rocket leaves decontamination and nutritional value

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    Plasma Activated Water (PAW) obtained by exposing water to cold atmospheric pressure plasma, has recently emerged as a promising alternative for food decontamination, compared to the use of traditional chemical sanitizers. The aim of the study was to evaluate the efficacy of PAW treatments for rocket salad decontamination. Washing with PAW for 2, 5, 10 and 20 min was assessed against different endogenous spoilage microorganisms and compared to untreated water and hypochlorite solution. The chemical composition of PAW as a function of treatment and delay time was characterized and the effect on product quality and nutritional parameters was evaluated. Results showed that PAW allowed an average reduction of 1.7–3 Log CFU/g for total mesophilic and psychrotrophic bacteria and Enterobacteriaceae following 2–5 min washing with minimal variation of qualitative and nutritional parameters. Overall, experimental results highlighted the potentiality of PAW treatments as a promising alternative to chlorine having the advantage of a minor adverse impact on environment and consumers' health. Industrial relevance: To meet consumers demand, the minimally processed fruit and vegetable industry needs to find sustainable solutions as alternative to the use of traditional chemical sanitizers that allow to increase product shelf-life and preserve safety, qualitative and nutritional characteristics. Plasma activated water represents a promising strategy for food decontamination, but its effects on foods have been only limitedly investigated. The present research is the first study on the use of plasma activated water on fresh rocket leaves, providing new and important information on microbial inactivation and quality of the fresh cut product

    Education for innovation and entrepreneurship in the food system: the Erasmus+ BoostEdu approach and results

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    Innovation and entrepreneurship are key factors to provide added value for food systems. Based on the findings of the Erasmus+ Strategic Partnership BoostEdu, the objective of this paper is to provide answers to three knowledge gaps: 1) identify the needs for innovation and entrepreneurship (I&E) in the food sector; 2) understand the best way to organize learning; 3) provide flexibility in turbulent times. BoostEdu aimed to provide a platform for continuing education within I&E for food professionals and was carried out through co-creation workshops and the development of an e-learning course. The results of the project in particular during the Covid-19 pandemics, highlighted the need for flexible access to modules that are complementary to other sources and based on a mix of theoretical concepts and practical experiences. The main lessons learned concern the need of co-creation and co-learning processes to identify suitable practices for the use of innovative digital technologies

    Velocity-resolved Reverberation Mapping of Five Bright Seyfert 1 Galaxies

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    We present the first results from a reverberation-mapping campaign undertaken during the first half of 2012, with additional data on one active galactic nucleus (AGN) (NGC 3227) from a 2014 campaign. Our main goals are (1) to determine the black hole masses from continuum-Hβ reverberation signatures, and (2) to look for velocity-dependent time delays that might be indicators of the gross kinematics of the broad-line region. We successfully measure Hβ time delays and black hole masses for five AGNs, four of which have previous reverberation mass measurements. The values measured here are in agreement with earlier estimates, though there is some intrinsic scatter beyond the formal measurement errors. We observe velocity-dependent Hβ lags in each case, and find that the patterns have changed in the intervening five years for three AGNs that were also observed in 2007.G.D.R., C.J.G., B.M.P., and R.W.P. are grateful for the support of the National Science Foundation through grant AST-1008882 to The Ohio State University. K.D.D., B.J.S., C.B.H., and J.L.V. acknowledge support by NSF Fellowships. M.C.B. gratefully acknowledges support from the NSF through CAREER grant AST-1253702. A.M.M. and D.M.S. acknowledge the support of NSF grants AST-1004756 and AST1009756. C.S.K. is supported by NSF grant AST-1515876. S.K. is supported at the Technion by the Kitzman Fellowship and by a grant from the Israel-Niedersachsen collaboration program. S.R. is supported at Technion by the Zeff Fellowship. S.G.S. acknowledges the support to CrAO in the frame of the “CosmoMicroPhysics” Target Scientific Research Complex Programme of the National Academy of Sciences of Ukraine (2007–2012). M.V. gratefully acknowledges support from the Danish Council for Independent Research via grant no. DFF 4002-00275. V.T.D. acknowledges the support of the Russian Foundation of Research (RF project no. 12-02-01237-a). The CrAO CCD cameras were purchased through the US Civilian Research and Development for Independent States of the Former Soviet Union (CRDF) awards UP1-2116 and UP1- 2549-CR-03. This research has been partly supported by the Grants-in-Aid of Scientific Research (17104002, 20041003, 21018003, 21018005, 22253002, and 22540247) of the Ministry of Education, Science, Culture and Sports of Japan. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administratio

    Runs of homozygosity in killer whale genomes provide a global record of demographic histories

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    Runs of homozygosity (ROH) occur when offspring inherit haplotypes that are identical by descent from each parent. Length distributions of ROH are informative about population history; specifically, the probability of inbreeding mediated by mating system and/or population demography. Here, we investigated whether variation in killer whale (Orcinus orca) demographic history is reflected in genome-wide heterozygosity and ROH length distributions, using a global data set of 26 genomes representative of geographic and ecotypic variation in this species, and two F1 admixed individuals with Pacific-Atlantic parentage. We first reconstructed demographic history for each population as changes in effective population size through time using the pairwise sequential Markovian coalescent (PSMC) method. We found a subset of populations declined in effective population size during the Late Pleistocene, while others had more stable demography. Genomes inferred to have undergone ancestral declines in effective population size, were autozygous at hundreds of short ROH (\u3c1 \u3eMb), reflecting high background relatedness due to coalescence of haplotypes deep within the pedigree. In contrast, longer and therefore younger ROH (\u3e1.5 Mb) were found in low latitude populations, and populations of known conservation concern. These include a Scottish killer whale, for which 37.8% of the autosomes were comprised of ROH \u3e1.5 Mb in length. The fate of this population, in which only two adult males have been sighted in the past five years, and zero fecundity over the last two decades, may be inextricably linked to its demographic history and consequential inbreeding depression

    Space Telescope and Optical Reverberation Mapping project. XI. Disk-wind characteristics and contributions to the very broad emission lines of NGC 5548

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    Funding: Support for HST program number GO-13330 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. We thank NSF (1816537, 1910687), NASA (17-ATP17-0141, 19-ATP19-0188), and STScI (HST-AR-15018, HST-AR-14556). MC acknowledges support from NASA through STScI grant HST-AR-14556.001-Aand NASA grant 19-ATP19-0188, and also support from National Science Foundation through grant AST-1910687.M.D. and G.F. and F. G. acknowledge support from the NSF (AST-1816537), NASA (ATP 17-0141), and STScI (HST-AR-13914, HST-AR-15018), and the Huffaker Scholarship. M.M. is supported by the Netherlands Organization for Scientific Research (NWO) through the Innovational Research Incentives Scheme Vidi grant 639.042.525. J.M.G. gratefully acknowledges support from NASA under the ADAP award 80NSSC17K0126. MV gratefully acknowledges support from the Independent Research Fund Denmark via grant number DFF 8021-00130.In 2014 the NGC 5548 Space Telescope and Optical Reverberation Mapping campaign discovered a two-month anomaly when variations in the absorption and emission lines decorrelated from continuum variations. During this time the soft X-ray part of the intrinsic spectrum had been strongly absorbed by a line-of-sight (LOS) obscurer, which was interpreted as the upper part of a disk wind. Our first paper showed that changes in the LOS obscurer produces the decorrelation between the absorption lines and the continuum. A second study showed that the base of the wind shields the broad emission-line region (BLR), leading to the emission-line decorrelation. In that study, we proposed the wind is normally transparent with no effect on the spectrum. Changes in the wind properties alter its shielding and affect the spectral energy distribution (SED) striking the BLR, producing the observed decorrelations. In this work we investigate the impact of a translucent wind on the emission lines. We simulate the obscuration using XMM-Newton, NuSTAR, and Hubble Space Telescope observations to determine the physical characteristics of the wind. We find that a translucent wind can contribute a part of the He ii and Fe Kα emission. It has a modest optical depth to electron scattering, which explains the fainter far-side emission in the observed velocity-delay maps. The wind produces the very broad base seen in the UV emission lines and may also be present in the Fe Kα line. Our results highlight the importance of accounting for the effects of such winds in the analysis of the physics of the central engine.Publisher PDFPeer reviewe

    Prototype ATLAS IBL Modules using the FE-I4A Front-End Readout Chip

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    The ATLAS Collaboration will upgrade its semiconductor pixel tracking detector with a new Insertable B-layer (IBL) between the existing pixel detector and the vacuum pipe of the Large Hadron Collider. The extreme operating conditions at this location have necessitated the development of new radiation hard pixel sensor technologies and a new front-end readout chip, called the FE-I4. Planar pixel sensors and 3D pixel sensors have been investigated to equip this new pixel layer, and prototype modules using the FE-I4A have been fabricated and characterized using 120 GeV pions at the CERN SPS and 4 GeV positrons at DESY, before and after module irradiation. Beam test results are presented, including charge collection efficiency, tracking efficiency and charge sharing.Comment: 45 pages, 30 figures, submitted to JINS
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