1,214 research outputs found

    Robust stabilization of singular-impulsive-delayed systems with nonlinear perturbations

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    Many dynamic systems in physics, chemistry, biology, engineering, and information science have impulsive dynamical behaviors due to abrupt jumps at certain instants during the dynamical process, and these complex dynamic behaviors can be modeled by singular impulsive differential systems. This paper formulates and studies a model for singular impulsive delayed systems with uncertainty from nonlinear perturbations. Several fundamental issues such as global exponential robust stabilization of such systems are established. A simple approach to the design of a robust impulsive controller is then presented. A numerical example is given for illustration of the theoretical results. Meanwhile, some new results and refined properties associated with the M-matrices and time-delay dynamic systems are derived and discussed.published_or_final_versio

    食管癌原發灶與淋巴結轉移灶細胞染色體變化特征的比較

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    BACKGROUND & OBJECTIVE: Local lymph node and blood metastasis could occur at early stage of esophageal squamous cell carcinoma (ESCC), which may be the key factors of its recurrence and poor prognosis. However, the mechanism of ESCC metastasis is unclear. This study was to analyze the genetic changes in primary lesion and lymph node metastases of ESCC, to screen for and locate ESCC metastasis-related genes. METHODS: Genomic alterations in 15 pairs of primary lesions and matched metastatic lymph nodes of ESCC were analyzed by comparative genomic hybridization (CGH). RESULTS: In the 15 pairs of tissues, the most common chromosomal alterations were the gains of 3q, 8q, 6p, 20p, 5p, 18p, 2p, 2q and 1q, and the losses of 10p, 10q, 17p, 18q, 4p and 13q. Of these changes, the most significant finding was the gain of 6p with a frequency of 47% in metastatic lymph nodes and 13% in primary lesions, and the gain of 20p with a frequency of 73% in metastatic lymph nodes and 33% in primary lesions. The second interesting finding was the loss of 10p with a frequency of 53% in metastatic lymph nodes and 13% in primary lesions, and the loss of 10q with a frequency of 47% in metastatic lymph nodes and 13% in primary lesions. CONCLUSION: The gains of 6p and 20p and the losses of 10p and 10q are common genomic alterations in primary lesion and lymph node metastases of ESCC, which may code ESCC metastasis-related genes.背景與目的:食管癌早期可發生局部淋巴或血行轉移,這是導致復發和預后差的主要原因。但是,食管癌轉移發生的分子機制尚不清楚。本研究旨在分析食管癌原發灶和淋巴結轉移灶腫瘤細胞染色體變化的特征,尋找或定位與食管癌轉移相關基因,加深對其轉移機制的了解。方法:應用比較基因組雜交技術(comparativegenomichybridization,CGH)分析15例食管癌患者原發灶和其對應的淋巴結轉移灶的染色體基因組改變。結果:最常見染色體DNA拷貝數增加的部位是3q,8q,6p,20p,5p,18p,2p,2q,1q;常見的染色體DNA拷貝數丟失的部位是10p,10q,17p,18q,4p,13q。其中,最有意義的發現是6p增加(原發灶:2/15,13%,轉移灶:7/15,47%),20p增加(原發灶:5/15,33.3%,轉移灶:11/15,73.3%)。第二個發現是10p丟失(原發灶:2/15,13.3%,轉移灶:8/15,53%),10q丟失(原發灶:2/15,13.3%,轉移灶:7/15,46.6%)。結論:食管癌原發灶和淋巴結轉移灶細胞染色體基因組改變最顯著的部位是6p,20p的增加和10p,10q的丟失;這些部位可能存在與食管癌細胞淋巴結轉移相關的基因。link_to_subscribed_fulltex

    A Schwarz lemma for K\"ahler affine metrics and the canonical potential of a proper convex cone

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    This is an account of some aspects of the geometry of K\"ahler affine metrics based on considering them as smooth metric measure spaces and applying the comparison geometry of Bakry-Emery Ricci tensors. Such techniques yield a version for K\"ahler affine metrics of Yau's Schwarz lemma for volume forms. By a theorem of Cheng and Yau there is a canonical K\"ahler affine Einstein metric on a proper convex domain, and the Schwarz lemma gives a direct proof of its uniqueness up to homothety. The potential for this metric is a function canonically associated to the cone, characterized by the property that its level sets are hyperbolic affine spheres foliating the cone. It is shown that for an nn-dimensional cone a rescaling of the canonical potential is an nn-normal barrier function in the sense of interior point methods for conic programming. It is explained also how to construct from the canonical potential Monge-Amp\`ere metrics of both Riemannian and Lorentzian signatures, and a mean curvature zero conical Lagrangian submanifold of the flat para-K\"ahler space.Comment: Minor corrections. References adde

    Observation of the electromagnetic doubly OZI-suppressed decay J/ψϕπ0J/\psi \rightarrow \phi \pi^{0}

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    Using a sample of 1.311.31 billion J/ψJ/\psi events accumulated with the BESIII detector at the BEPCII collider, we report the observation of the decay J/ψϕπ0J/\psi \rightarrow \phi\pi^{0}, which is the first evidence for a doubly Okubo-Zweig-Iizuka suppressed electromagnetic J/ψJ/\psi decay. A clear structure is observed in the K+KK^{+} K^{-} mass spectrum around 1.02 GeV/c2c^2, which can be attributed to interference between J/ψϕπ0J/\psi \rightarrow \phi\pi^{0} and J/ψK+Kπ0J/\psi \rightarrow K^{+}K^{-}\pi^{0} decays. Due to this interference, two possible solutions are found. The corresponding measured values of the branching fraction of J/ψϕπ0J/\psi \to \phi\pi^{0} are [2.94±0.16(stat.)±0.16(syst.)]×106[2.94 \pm 0.16\text{(stat.)} \pm 0.16\text{(syst.)}] \times 10^{-6} and [1.24±0.33(stat.)±0.30(syst.)]×107[1.24 \pm 0.33\text{(stat.)} \pm 0.30\text{(syst.)}] \times 10^{-7}.Comment: 7 pages, 4 figures, published in Phys. Rev.

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector

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    This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}andcorrespondtoanintegratedluminosityof and correspond to an integrated luminosity of 4.6\;{\rm f}{{{\rm b}}^{-1}}.ThemeasurementisperformedbyreconstructingtheboostedWorZbosonsinsinglejets.ThereconstructedjetmassisusedtoidentifytheWandZbosons,andajetsubstructuremethodbasedonenergyclusterinformationinthejetcentreofmassframeisusedtosuppressthelargemultijetbackground.ThecrosssectionforeventswithahadronicallydecayingWorZboson,withtransversemomentum. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum {{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}andpseudorapidity and pseudorapidity |\eta |\lt 1.9,ismeasuredtobe, is measured to be {{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques

    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

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    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Search for pair-produced long-lived neutral particles decaying to jets in the ATLAS hadronic calorimeter in ppcollisions at √s=8TeV

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    The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3fb−1of data collected in proton–proton collisions at √s=8TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeVto 900 GeV, and a long-lived neutral particle mass from 10 GeVto 150 GeV

    Horizontal gene transfer in silkworm, Bombyx mori

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    <p>Abstract</p> <p>Background</p> <p>The domesticated silkworm, <it>Bombyx mori</it>, is the model insect for the order Lepidoptera, has economically important values, and has gained some representative behavioral characteristics compared to its wild ancestor. The genome of <it>B. mori </it>has been fully sequenced while function analysis of <it>BmChi-h </it>and <it>BmSuc1 </it>genes revealed that horizontal gene transfer (HGT) maybe bestow a clear selective advantage to <it>B. mori</it>. However, the role of HGT in the evolutionary history of <it>B. mori </it>is largely unexplored. In this study, we compare the whole genome of <it>B. mori </it>with those of 382 prokaryotic and eukaryotic species to investigate the potential HGTs.</p> <p>Results</p> <p>Ten candidate HGT events were defined in <it>B. mori </it>by comprehensive sequence analysis using Maximum Likelihood and Bayesian method combining with EST checking. Phylogenetic analysis of the candidate HGT genes suggested that one HGT was plant-to- <it>B. mori </it>transfer while nine were bacteria-to- <it>B. mori </it>transfer. Furthermore, functional analysis based on expression, coexpression and related literature searching revealed that several HGT candidate genes have added important characters, such as resistance to pathogen, to <it>B. mori</it>.</p> <p>Conclusions</p> <p>Results from this study clearly demonstrated that HGTs play an important role in the evolution of <it>B. mori </it>although the number of HGT events in <it>B. mori </it>is in general smaller than those of microbes and other insects. In particular, interdomain HGTs in <it>B. mori </it>may give rise to functional, persistent, and possibly evolutionarily significant new genes.</p
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