109 research outputs found

    Everything is digital: Getting ready for the inevitable changes

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    In vitro shoot regeneration from seedling explants in Brassica vegetables: Red cabbage, broccoli, Savoy cabbage and cauliflower

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    Brassica oleracea varieties (red cabbage, broccoli, Savoy cabbage and cauliflower) were tested for their ability to regenerate shoots in vitro. Cotyledon, hypocotyl and root explants of 7 day-old seedlings were incubated on Murashige and Skoog's (MS) medium supplemented with 1 mg l-1 6-benzyladenine (BA) or 6-furfurylaminopurine (KIN) in combination with 0, 0.1, and 0.2 mg l-1 indole-3-butyric acid (IBA). Hypocotyls showed the best explants in almost all varieties tested with a minimum regeneration potential of 75% and producing 3.5-7.4 shoots per explant. The BA-supplemented media were optimal for both shoot regeneration and multiplication. Shoots rooted maximally (100%) on plant growth regulator-free MS medium containing 2% or 4% sucrose. Increased sucrose content improved plant acclimation in the greenhouse.Ispitivana je sposobnost četiri varijeteta Brassica oleracea (crveni kupus, brokoli, kelj i karfiol) da regenerišu pupoljke in vitro. Eksplantati kotiledona, hipokotila i korenova, uzetih sa 7 dana starih klijanaca, su gajeni na Murashige i Skoog (MS) hranljivoj podlozi sa dodatkom 1 mg l-1 6-benziladenina (BA) ili 6- furfurilaminopurina (KIN) u kombinaciji sa 0, 0.1, i 0.2 mg l-1 indol-3-butirične kiseline (IBA). Eksplantati hipokotila su se pokazali kao najbolji za regeneraciju kod skoro svih testiranih varijeteta sa minimalnim regenerativnim potencijalom od 75% i sa produkcijom 3.5- 7.4 pupoljaka po eksplantatu. Podloge koje su sadržale BA su bile optimalne, kako za regeneraiju pupoljaka, tako i za njihovu kasniju multiplikaciju. Maksimalan procenat oživljavanja izdanaka (100%) je postignut na MS medijumu bez dodatih regulatora rastenja, a koji je sadržao 2% ili 4% saharozu. Povećan sadržaj saharoze u medijumu za ožiljavanje uticao je na poboljšanu aklimatizaciju biljaka u stakleniku.Projekat ministarstva br. 143026 i TR-20072

    Search for long-lived particles in events with photons and missing energy in proton-proton collisions at root s=7 TeV

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    Results are presented from a search for long-lived neutralinos decaying into a photon and an invisible particle, a signature associated with gauge-mediated supersymmetry breaking in supersymmetric models. The analysis is based on a 4.9 fb(-1) sample of proton-proton collisions at root s = 7 TeV, collected with the CMS detector at the LHC. The missing transverse energy and the time of arrival of the photon at the electromagnetic calorimeter are used to search for an excess of events over the expected background. No significant excess is observed, and lower limits at the 95% confidence level are obtained on the mass of the lightest neutralino, m GT 220 GeV (for c tau LT 500 mm), as well as on the proper decay length of the lightest neutralino, c tau GT 6000 mm (for m LT 150 GeV). (c) 2013 CERN. Published by Elsevier B.V. All rights reserved

    Measurement of the t(t)over-bar production cross section in the dilepton channel in pp collisions at root s=8 TeV

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    The top-antitop quark (t (t) over bar) production cross section is measured in proton-proton collisions at root s = 8 TeV with the CMS experiment at the LHC, using a data sample corresponding to an integrated luminosity of 5.3 fb(-1). The measurement is performed by analysing events with a pair of electrons or muons, or one electron and one muon, and at least two jets, one of which is identified as originating from hadronisation of a bottom quark. The measured cross section is 239 +/- 2 (stat.) +/- 11 (syst.) +/- 6 (lum.) pb, for an assumed top-quark mass of 172.5 GeV, in agreement with the prediction of the standard model

    Measurement of the Inclusive Jet Cross Section in pp Collisions at root s=7 TeV

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    The inclusive jet cross section is measured in pp collisions with a center-of-mass energy of 7 TeV at the Large Hadron Collider using the CMS experiment. The data sample corresponds to an integrated luminosity of 34 pb(-1). The measurement is made for jet transverse momenta in the range 18-1100 GeV and for absolute values of rapidity less than 3. The measured cross section extends to the highest values of jet p(T) ever observed and, within the experimental and theoretical uncertainties, is generally in agreement with next-to-leading-order perturbative QCD predictions

    Measurement of the t-Channel Single Top Quark Production Cross Section in pp Collisions at root s=7 TeV

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    Electroweak production of the top quark is measured for the first time in pp collisions at root s = 7 TeV, using a data set collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb(-1). With an event selection optimized for t-channel production, two complementary analyses are performed. The first one exploits the special angular properties of the signal, together with background estimates from the data. The second approach uses a multivariate analysis technique to probe the compatibility with signal topology expected from electroweak top-quark production. The combined measurement of the cross section is 83.6 +/- 29.8 (stat + syst) +/- 3.3(lumi) pb, consistent with the standard model expectation

    Search for gluino mediated bottom- and top-squark production in multijet final states in pp collisions at 8 TeV

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    A search for supersymmetry is presented based on events with large missing transverse energy, no isolated electron or muon, and at least three jets with one or more identified as a bottom-quark jet. A simultaneous examination is performed of the numbers of events in exclusive bins of the scalar sum of jet transverse momentum values, missing transverse energy, and bottom-quark jet multiplicity. The sample, corresponding to an integrated luminosity of 19.4 fb(-1), consists of proton-proton collision data recorded at a center-of-mass energy of 8 TeV with the CMS detector at the LHC in 2012. The observed numbers of events are found to be consistent with the standard model expectation, which is evaluated with control samples in data. The results are interpreted in the context of two simplified supersymmetric scenarios in which gluino pair production is followed by the decay of each gluino to an undetected lightest supersymmetric particle and either a bottom or top quark-antiquark pair, characteristic of gluino mediated bottom- or top-squark production. Using the production cross section calculated to next-to-leading-Order plus next-to-leading-logarithm accuracy, and in the limit of a massless lightest supersymmetric particle, we exclude gluinos with masses below 1170 GeV and 1020 GeV for the two scenarios, respectively. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved

    Measurement of the Drell-Yan cross section in pp collisions at root s=7 TeV

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    The Drell-Yan differential cross section is measured in pp collisions at root s = 7 TeV, from a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 36 pb(-1). The cross section measurement, normalized to the measured cross section in the Z region, is reported for both the dimuon and dielectron channels in the dilepton invariant mass range 15-600 GeV. The normalized cross section values are quoted both in the full phase space and within the detector acceptance. The effect of final state radiation is also identified. The results are found to agree with theoretical predictions
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