317 research outputs found

    Expression analysis of the 35S CaMV promoter and its derivatives in transgenic hairy root cultures of cucumber (Cucumis sativus) generated by Agrobacterium rhizogenes infection

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    The cauliflower mosaic virus (CaMV) 35S promoter is the most commonly used viral-based promoter to drive transgene expression in plants. Although, many studies have demonstrated the constitutive nature of this promoter, some reports have suggested varied expression levels in different parts of the plant. Therefore, our aim was to study the activity of the CaMV 35S promoter in the hairy root system. The CaMV 35S promoter, the duplicate CaMV 35S promoter (designated CaMV 35ST) and the duplicate CaMV 35S promoter containing a 5’- untranslated leader sequence from the alfalfa mosaic virus RNA4 promoter (designated CaMV 35ST/AMV) were compared to evaluate their effects on the expression of the gus reporter gene in transgenic hairy roots, which was mediated using the Agrobacterium rhizogenes A4 transformation system. The integration of T-DNA containing a gus reporter gene in hairy root lines was confirmed at low copy numbers ranging from 1 to 4 copies using quantitative real-time PCR. Histochemical staining of cucumber hairy roots showed over-expression of the gus gene when driven with the CaMV 35S promoter. The expression of the gus gene when driven with the CaMV 35ST promoter showed a lower expression than that driven by the CaMV 35S promoter. However, the expression of the gus gene driven by the CaMV 35ST/AMV promoter was slightly higher than that driven by the CaMV 35ST promoter. In this study, the reduced activity of the CaMV 35ST promoter was observed for the first time. Further investigation is required to elucidate the factors that mediate the decline in promoter activity.Key words: Cucumis sativus L, hairy root, Agrobacterium rhizogenes, promoter 35S cauliflower mosaic virus (CaMV), β-glucuronidase (GUS), 5’UTR AMV

    Search for Dark Matter and Supersymmetry with a Compressed Mass Spectrum in the Vector Boson Fusion Topology in Proton-Proton Collisions at root s=8 TeV

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    Optimization of 4D/3D printing via machine learning: a systematic review

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    This systematic review explores the integration of 4D/3D printing technologies with machine learning, shaping a new era of manufacturing innovation. The analysis covers a wide range of research papers, articles, and patents, presenting a multidimensional perspective on the advancements in additive manufacturing. The review underscores machine learning's pivotal role in optimizing 4D/3D printing, addressing aspects like design customization, material selection, process control, and quality assurance. The examination reveals novel techniques enabling the fabrication of intelligent, self-adaptive structures capable of transformation over time. Additionally, the review investigates the use of predictive algorithms to enhance efficiency, reliability, and sustainability in 4D/3D printing processes. Applications span aerospace, healthcare, architecture, and consumer goods, showcasing the potential to create intricate, personalized, and once-unattainable functional products. The synergy between machine learning and 4D/3D printing is poised to unlock new manufacturing horizons, enabling rapid responses to market demands and sustainability challenges. In summary, this review provides a comprehensive overview of the current state of 4D/3D printing optimization through machine learning, highlighting the transformative potential of this interdisciplinary fusion and offering a roadmap for future research and development. It aims to inspire innovators, researchers, and industries to harness this powerful combination for accelerated evolution in manufacturing processes into the 21st century and beyond

    Search for central exclusive production of top quark pairs in proton-proton collisions at √s=13 TeV with tagged protons

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    A search for the central exclusive production of top quark-antiquark pairs (tt) is performed for the frst time using proton-tagged events in proton-proton collisions at the LHC at a centre-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 29.4 fb−1 . The tt decay products are reconstructed using the central CMS detector, while forward protons are measured in the CMS-TOTEM precision proton spectrometer. An observed (expected) upper bound on the production cross section of 0.59 (1.14) pb is set at 95% confdence level, for collisions of protons with fractional momentum losses between 2 and 20%

    Evidence for Top Quark Production in Nucleus-Nucleus Collisions

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    A Deep Neural Network for Simultaneous Estimation of b Jet Energy and Resolution

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    We describe a method to obtain point and dispersion estimates for the energies of jets arising from b quarks produced in proton-proton collisions at an energy of s = 13 TeV at the CERN LHC. The algorithm is trained on a large sample of simulated b jets and validated on data recorded by the CMS detector in 2017 corresponding to an integrated luminosity of 41 fb - 1 . A multivariate regression algorithm based on a deep feed-forward neural network employs jet composition and shape information, and the properties of reconstructed secondary vertices associated with the jet. The results of the algorithm are used to improve the sensitivity of analyses that make use of b jets in the final state, such as the observation of Higgs boson decay to b b ¯

    Measurement of inclusive very forward jet cross sections in proton-lead collisions at \sqrt{sNN} = 5:02 TeV

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    Measurements of differential cross sections for inclusive very forward jet production in proton-lead collisions as a function of jet energy are presented. The data were collected with the CMS experiment at the LHC in the laboratory pseudorapidity range −6.6 < η < −5.2. Asymmetric beam energies of 4 TeV for protons and 1.58 TeV per nucleon for Pb nuclei were used, corresponding to a center-of-mass energy per nucleon pair of \sqrt{sNN} = 5:02 TeV. Collisions with either the proton (p+Pb) or the ion (Pb+p) traveling towards the negative η hemisphere are studied. The jet cross sections are unfolded to stable-particle level cross sections with p_{T} ≳ 3 GeV, and compared to predictions from various Monte Carlo event generators. In addition, the cross section ratio of p+Pb and Pb+p data is presented. The results are discussed in terms of the saturation of gluon densities at low fractional parton momenta. None of the models under consideration describes all the data over the full jet-energy range and for all beam configurations. Discrepancies between the differential cross sections in data and model predictions of more than two orders of magnitude are observed

    Evidence for electroweak production of four charged leptons and two jets in proton-proton collisions at √<i>s</i>=13 TeV

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    Search for an exotic decay of the Higgs boson to a pair of light pseudoscalars in the final state with two bquarks and two tau leptons in proton-proton collisions at root s=13 TeV The CMS Collaboration

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    A search for an exotic decay of the Higgs boson to a pair of light pseudoscalar bosons is performed for the first time in the final state with two b quarks and two tau leptons. The search is motivated in the context of models of physics beyond the standard model (SM), such as two Higgs doublet models extended with a complex scalar singlet (2HDM + S), which include the next-to-minimal supersymmetric SM (NMSSM). The results are based on a data set of proton-proton collisions corresponding to an integrated luminosity of 35.9 fb(-1), accumulated by the CMS experiment at the LHC in 2016 at a center-of-mass energy of 13 TeV. Masses of the pseudoscalar boson between 15 and 60 GeVare probed, and no excess of events above the SM expectation is observed. Upper limits between 3 and 12% are set on the branching fraction B(h -> aa -> 2 tau 2b) assuming the SM production of the Higgs boson. Upper limits are also set on the branching fraction of the Higgs boson to two light pseudoscalar bosons in different 2HDM + S scenarios. Assuming the SM production cross section for the Higgs boson, the upper limit on this quantity is as low as 20% for a mass of the pseudoscalar of 40 GeV in the NMSSM. (C) 2018 The Author(s). Published by Elsevier B.V.Peer reviewe
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