13,481 research outputs found

    Entomopathogenic nematodes for biological control of codling moth

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    Entomopathogenic nematodes are often found naturally infecting codling moth larvae. The effect of an autumn treatment with S. feltiae on the fruit damage in the following summer was evaluated by treating 4 different apple orchards in October 2004 and 2005 at application rates of 3.75; 2 and 1.5 billion nematodes in 4000 l / ha. In three of the treated orchards, one treated with 3.75x109 nematodes/ha the other two treated with 2e9 nematode/ha, reduction in fruit damage was around 50%. In the most heavily infested orchard, which was treated with 1.5x109 nematode/ha only 33% reduction in fruit damage was achieved. Compared to previous studies, this was the first assessing the effect on the fruit damage in the summer following the treatment rather than assessing the mortality of sentinel larvae fixed to the treated tree trunks

    Renormalization of dimension-six operators relevant for the Higgs decays h→γγ,γZh\rightarrow \gamma\gamma,\gamma Z

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    The discovery of the Higgs boson has opened a new window to test the SM through the measurements of its couplings. Of particular interest is the measured Higgs coupling to photons which arises in the SM at the one-loop level, and can then be significantly affected by new physics. We calculate the one-loop renormalization of the dimension-six operators relevant for h→γγ,γZh\rightarrow \gamma\gamma, \gamma Z, which can be potentially important since it could, in principle, give log-enhanced contributions from operator mixing. We find however that there is no mixing from any current-current operator that could lead to this log-enhanced effect. We show how the right choice of operator basis can make this calculation simple. We then conclude that h→γγ,γZh\rightarrow \gamma\gamma, \gamma Z can only be affected by RG mixing from operators whose Wilson coefficients are expected to be of one-loop size, among them fermion dipole-moment operators which we have also included.Comment: 21 pages. Improved version with h -> gamma Z results added and structure of anomalous-dimension matrix determined further. Conclusions unchange

    A Near-Infrared L Band Survey of the Young Embedded Cluster NGC 2024

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    We present the results of the first sensitive L band (3.4 micron) imaging study of the nearby young embedded cluster NGC 2024. Two separate surveys of the cluster were acquired in order to obtain a census of the circumstellar disk fraction in the cluster. From an analysis of the JHKL colors of all sources in our largest area, we find an infrared excess fraction of > 86%. The JHKL colors suggest that the infrared excesses arise in circumstellar disks, indicating that the majority of the sources which formed in the NGC 2024 cluster are currently surrounded by, and likely formed with circumstellar disks. The excess fractions remain very high, within the errors, even at the faintest L magnitudes from our deeper surveys suggesting that disks form around the majority of the stars in very young clusters such as NGC 2024 independent of mass. From comparison with published JHKL observations of Taurus, we find the K - L excess fraction in NGC 2024 to be consistent with a high initial incidence of circumstellar disks in both NGC 2024 and Taurus. Because NGC 2024 represents a region of much higher stellar density than Taurus, this suggests that disks may form around most of the YSOs in star forming regions independent of environment. We find a relatively constant JHKL excess fraction with increasing cluster radius, indicating that the disk fraction is independent of location in the cluster. In contrast, the JHK excess fraction increases rapidly toward the central region of the cluster, and is most likely due to contamination of the K band measurements by bright nebulosity in the central regions of the cluster. We identify 45 candidate protostellar sources in the central regions of the NGC 2024 cluster, and find a lower limit on the protostellar phase of early stellar evolution of 0.4 - 1.4 X 10^5 yr, similar to that in Taurus.Comment: 37 pages, 8 figures, 3 tables, To appear in the Astronomical Journa

    Thrombolysis for Cerebral Ischemia

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    The care for patients with acute ischemic stroke has been revolutionized by the clinical application of fibrinolysis. Intravenous recombinant tissue plasminogen activator (rt-PA) has been proven to improve functional outcomes following acute ischemic stroke and can be administered to a select group of patients up to 4.5 h after symptom onset. Time from symptom onset to thrombolysis is the most important determinant of the success of treatment, with greatest efficacy if given within 90 min. Hospitals should implement standardized processes and protocols for acute stroke to guide immediate patient assessment, brain imaging, drug administration, and post-thrombolysis care. In this article we review the clinical application of thrombolysis, care of acute stroke patients, current evidence regarding fibrinolysis, and future direction of penumbral imaging to select candidates for reperfusion therapies

    The eruptive history and magmatic evolution of Aluto volcano: new insights into silicic peralkaline volcanism in the Ethiopian rift

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    The silicic peralkaline volcanoes of the East African Rift are some of the least studied volcanoes on Earth. Here we bring together new constraints from fieldwork, remote sensing, geochronology and geochemistry to present the first detailed account of the eruptive history of Aluto, a restless silicic volcano located in a densely populated section of the Main Ethiopian Rift. Prior to the growth of the Aluto volcanic complex (before 500 ka) the region was characterized by a significant period of fault development and mafic fissure eruptions. The earliest volcanism at Aluto built up a trachytic complex over 8 km in diameter. Aluto then underwent large-volume ignimbrite eruptions at 316 ± 19 ka and 306 ± 12 ka developing a ~ 42 km2 collapse structure. After a hiatus of ~ 250 ka, a phase of post-caldera volcanism initiated at 55 ± 19 ka and the most recent eruption of Aluto has a radiocarbon age of 0.40 ± 0.05 cal. ka BP. During this post-caldera phase highly-evolved peralkaline rhyolite lavas, ignimbrites and pumice fall deposits have erupted from vents across the complex. Geochemical modelling is consistent with rhyolite genesis from protracted fractionation (> 80%) of basalt that is compositionally similar to rift-related basalts found east of the complex. Based on the style and volume of recent eruptions we suggest that silicic eruptions occur at an average rate of 1 per 1000 years, and that future eruptions of Aluto will involve explosive emplacement of localised pumice cones and effusive obsidian coulees of volumes in the range 1–100 × 106 m3

    The supernova impostor PSN J09132750+7627410 and its progenitor

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    We report the results of our follow-up campaign of the supernova impostor PSN J09132750+7627410, based on optical data covering ∼250 d\sim250\,\rm{d}. From the beginning, the transient shows prominent narrow Balmer lines with P-Cygni profiles, with a blue-shifted absorption component becoming more prominent with time. Along the ∼3 months\sim3\,\rm{months} of the spectroscopic monitoring, broad components are never detected in the hydrogen lines, suggesting that these features are produced in slowly expanding material. The transient reaches an absolute magnitude Mr=−13.60±0.19 magM_r=-13.60\pm0.19\,\rm{mag} at maximum, a typical luminosity for supernova impostors. Amateur astronomers provided ∼4 years\sim4\,\rm{years} of archival observations of the host galaxy, NGC 2748. The detection of the quiescent progenitor star in archival images obtained with the Hubble Space Telescope suggests it to be an 18−2018-20\msun white-yellow supergiant.Comment: 7 pages, 4 figures, supplemental material available in the source file. Accepted for publication on Astrophysical Journal Letter

    Report of the second Sinana woreda strategic innovation platform meeting, 14 December 2014

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    Emotions, Violence and Social Belonging: an Eliasian Analysis of Sports Spectatorship

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    This paper examines the development of different forms of spectator violence in terms of the socio-temporal structure of situational dynamics at Gaelic football matches in Ireland. The nature of violent encounters has shifted from a collective form based on local solidarity and a reciprocal code of honour, through a transitional collective form based on deferred emotional satisfaction and group pride, towards increasing individualization of spectator violence. This occurs due to the shifting objects of emotional involvement. As the functional specialization of the various roles in the game is partially accepted by spectators, the referee becomes the target of anger. Violence becomes more individualized as ‘mutually expected self-restraint’ proceeds within the context of relative state pacification beyond the field of play and the formation of a less volatile habitus. We use Elias’s figurational perspective on violence over the micro-interactional approach of Randall Collins, but support Collins’ emphasis on state legitimacy
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