302 research outputs found

    Poly(ADP-ribose)polymerase activity controls plant growth by promoting leaf cell number

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    A changing global environment, rising population and increasing demand for biofuels are challenging agriculture and creating a need for technologies to increase biomass production. Here we demonstrate that the inhibition of poly (ADPribose) polymerase activity is a promising technology to achieve this under non-stress conditions. Furthermore, we investigate the basis of this growth enhancement via leaf series and kinematic cell analysis as well as single leaf transcriptomics and plant metabolomics under non-stress conditions. These data indicate a regulatory function of PARP within cell growth and potentially development. PARP inhibition enhances growth of Arabidopsis thaliana by enhancing the cell number. Time course single leaf transcriptomics shows that PARP inhibition regulates a small subset of genes which are related to growth promotion, cell cycle and the control of metabolism. This is supported by metabolite analysis showing overall changes in primary and particularly secondary metabolism. Taken together the results indicate a versatile function of PARP beyond its previously reported roles in controlling plant stress tolerance and thus can be a useful target for enhancing biomass production

    Comparison of Diagnostic Profiles of Deaf and Hearing Children with a Diagnosis of Autism.

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    There is limited research comparing the presentation of autism in deaf and hearing children and young people. These comparisons are important to facilitate accurate diagnosis, as rates of misdiagnosis and delay in diagnosis amongst deaf children and young people are high. The aim of this study was to compare diagnostic assessment profiles of a UK cohort of autistic deaf and hearing children and young people. The Autism Diagnostic Interview-Revised-Deaf adaptation was completed with the parents of 106 children and young people (deaf children = 65; hearing children = 41). The majority of items explored showed no significant differences between deaf and hearing children and young people. Differences were found in peer relationships, where autistic deaf participants were less likely to respond to the approaches of other children or play imaginatively with peers. These findings need to be taken into consideration by clinicians in the assessment process

    A search for J^{PC}=1^{-+} exotic mesons in the pi- pi- pi+ and pi- pi0 pi0 systems

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    A partial wave analysis (PWA) of the pi-pi-pi+ and pi-pi0pi0 systems produced in the reaction pi- p -> (3pi)-p at 18 GeV/c was carried out using an isobar model assumption. This analysis is based on 3.0M pi-pi0pi0 events and 2.6M pi-pi-pi+ events and shows production of the a2(1320), pi2(1670) and \pi(1800) mesons. An earlier analysis of 250K pi-pi-pi+ events from the same experiment showed possible evidence for a J^{PC}=1^{-+}$ exotic meson with a mass of 1.6 GeV/c^2 decaying into rho pi. In this analysis of a higher statistics sample of the (3pi)- system in two charged modes we find no evidence of an exotic meson.Comment: 4 pages, 5 figures, added comment about the negative reflectivity exotic wave

    The Evidence for a Pentaquark Signal and Kinematic Reflections

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    Several recent experiments have reported evidence for a narrow baryon resonance with positive strangeness (Θ+\Theta^+) at a mass of 1.54 GeV/c2c^2. Baryons with S=+1S=+1 cannot be conventional qqqqqq states and the reports have thus generated much theoretical speculation about the nature of possible S=+1S=+1 baryons, including a 5-quark, or pentaquark, interpretation. We show that narrow enhancements in the K+nK^+n effective mass spectrum can be generated as kinematic reflections resulting from the decay of mesons, such as the f2(1275)f_2(1275), the a2(1320)a_2(1320) and the ρ3(1690)\rho_3(1690).Comment: 4 pages, 4 figure

    Incremental bounded model checking for embedded software

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    Program analysis is on the brink of mainstream usage in embedded systems development. Formal verification of behavioural requirements, finding runtime errors and test case generation are some of the most common applications of automated verification tools based on bounded model checking (BMC). Existing industrial tools for embedded software use an off-the-shelf bounded model checker and apply it iteratively to verify the program with an increasing number of unwindings. This approach unnecessarily wastes time repeating work that has already been done and fails to exploit the power of incremental SAT solving. This article reports on the extension of the software model checker CBMC to support incremental BMC and its successful integration with the industrial embedded software verification tool BTC EMBEDDED TESTER. We present an extensive evaluation over large industrial embedded programs, mainly from the automotive industry. We show that incremental BMC cuts runtimes by one order of magnitude in comparison to the standard non-incremental approach, enabling the application of formal verification to large and complex embedded software. We furthermore report promising results on analysing programs with arbitrary loop structure using incremental BMC, demonstrating its applicability and potential to verify general software beyond the embedded domain

    A Study of the \eta \pi^{0} Spectrum and Search for a J^{PC} = 1^{-+} Exotic Meson

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    A partial wave analysis (PWA) of the of the ηπ0\eta \pi ^0 system (where ηγγ\eta \to \gamma \gamma) produced in the charge exchange reaction πpηπ0n\pi ^-p\to \eta \pi ^0n at an incident momentum of 18 GeV/c/c is presented as a function of ηπ0{\eta \pi ^0} invariant mass, mηπ0m_{\eta\pi^0}, and momentum transfer squared, tπηπt_{\pi^{-}\to\eta\pi}, from the incident π\pi^- to the outgoing ηπ0{\eta\pi ^0} system. SS, PP and DD waves were included in the PWA. The a0(980)a_0(980) and a2(1320)a_2(1320) states are clearly observed in the overall ηπ0{\eta\pi ^0} effective mass distribution as well as in the amplitudes associated with SS wave and DD waves respectively after partial wave decomposition. The observed distributions in moments (averages of spherical harmonics) were compared to the results from the PWA and the two are consistent. The distribution in tπηπt_{\pi^{-}\to\eta\pi} for individual DD waves associated with natural and unnatural parity exchange in the tt-channel are consistent with Regge phenomenology. Of particular interest in this study is the PP wave since this leads to an exotic JPC=1+J^{PC}=1^{-+} for the ηπ\eta \pi system. A PP wave is present in the data, however attempts to describe the mass dependence of the amplitude and phase motion with respect to the DD wave as a Breit-Wigner resonance are problematic. This has implications regarding the existence of a reported exotic JPC=1+J^{PC} = 1^{-+} meson decaying into ηπ0\eta \pi^0 with a mass near 1.4 GeV/c2/c^2.Comment: 19 pages, 29 figures, to appear in Phys. Rev.

    Flatte-like distributions and the a_0(980)/f_0(980) mesons

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    We explore the features of Flatte-like parametrizations. In particular, we demonstrate that the large variation in the absolute values of the coupling constants to the pi-eta (or pi-pi) and KKbar channels for the a_0(980) and f_0(980) mesons that one can find in the literature can be explained by a specific scaling behaviour of the Flatte amplitude for energies near the KKbar threshold. We argue that the ratio of the coupling constants can be much better determined from a fit to experimental data.Comment: 12 pages, 12 figure

    Aspects of a0-f0 mixing in the reaction pn->da0

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    Some aspects of a0-f0 mixing effects in the reaction pnda00{\vec p} n\to da^0_0 with perpendicular polarized proton beam are discussed. An angular--asymmetry parameter AA is defined to study those effects. It is shown that, for energies close to the production threshold, the angular--asymmetry parameter A(θ,ϕ)A(\theta, \phi) is proportional to the a0-f0 mixing amplitude for arbitrary polar and azimuthal angles θ\theta and ϕ\phi of the outgoing a0a_0 meson. This statement is also valid for arbitrary energies, but then only at polar angles θ=00\theta=0^0 and θ=900\theta=90^0. The mass dependence of the differential cross section dσ/dmπ0ηd\sigma/dm_{\pi^0\eta} in the reaction pndπ0ηpn\to d\pi^0\eta in the presence of \mix mixing is also discussed.Comment: 17 pages, 3 Figure

    Evidence that the a0(980) and f0(980) are not elementary particles

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    We study the interesting problem of whether it is possible to distinguish composite from elementary particles. In particular we generalize a model-independent approach of S. Weinberg to the case of unstable particles. This allows us to apply our formalism to the case of the a0(980) and f0(980) resonances and to address the question whether these particles are predominantly genuine, confined quark states (of qˉq\bar q q or qqqˉqˉqq\bar q\bar q structure) or governed by mesonic components.Comment: 15 pages, 4 Figure
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