3,717 research outputs found

    Cervical abscess in an immunocompetent patient with Mycobacterium malmoense pulmonary disease

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    BACKGROUND: Mycobacterium malmoense is a nontuberculous mycobacteria seen mainly in two age groups and with different clinical presentations. Most patients are male adults presenting clinical symptoms and signs similar to those of pulmonary tuberculosis. The second group is formed by immunocompetent children with localized cervical lymphadenitis. Although cervical adenitis is the main extrapulmonary manifestation of M. malmoense, virtually all cases of cervical disease were documented in children. Disseminated disease is rare and has been reported in patients with severely impaired immunity. CASE REPORT: We report a case of a 47-year-old immunocompetent man with a cervical abscess, in whom we identified a M. malmoense pulmonary disease with multiple cervical, thoracic and abdominal adenopathies. CONCLUSION: Extrapulmonary infection due to M. Malmoense needs to be considered on the differential diagnosis of cervical masses and adenopathies, not only in pediatric patients but also in adults with no impaired immunity. A high index of suspicion for nontuberculous mycobacteria is essential for the diagnosis and prognosis

    Offshore Wind Energy Conversion System Connected to the Electric Grid: Modeling and Simulation

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    This paper is on modeling and simulation for an offshore wind system equipped with a semi-submersible floating platform, a wind turbine, a permanent magnet synchronous generator, a multiple point clamped four level or five level full-power converter, a submarine cable and a second order filter. The drive train is modeled by three mass model considering the resistant stiffness torque, structure and tower in deep water due to the moving surface elevation. The system control uses PWM by space vector modulation associated with sliding mode and proportional integral controllers. The electric energy is injected into the electric grid either by an alternated current link or by a direct current link. The model is intend to be a useful tool for unveil the behavior and performance of the offshore wind system, especially for the multiple point clamped full-power converter, under normal operation or under malfunctions

    Universal features of correlated bursty behaviour

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    Inhomogeneous temporal processes, like those appearing in human communications, neuron spike trains, and seismic signals, consist of high-activity bursty intervals alternating with long low-activity periods. In recent studies such bursty behavior has been characterized by a fat-tailed inter-event time distribution, while temporal correlations were measured by the autocorrelation function. However, these characteristic functions are not capable to fully characterize temporally correlated heterogenous behavior. Here we show that the distribution of the number of events in a bursty period serves as a good indicator of the dependencies, leading to the universal observation of power-law distribution in a broad class of phenomena. We find that the correlations in these quite different systems can be commonly interpreted by memory effects and described by a simple phenomenological model, which displays temporal behavior qualitatively similar to that in real systems

    Theories for influencer identification in complex networks

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    In social and biological systems, the structural heterogeneity of interaction networks gives rise to the emergence of a small set of influential nodes, or influencers, in a series of dynamical processes. Although much smaller than the entire network, these influencers were observed to be able to shape the collective dynamics of large populations in different contexts. As such, the successful identification of influencers should have profound implications in various real-world spreading dynamics such as viral marketing, epidemic outbreaks and cascading failure. In this chapter, we first summarize the centrality-based approach in finding single influencers in complex networks, and then discuss the more complicated problem of locating multiple influencers from a collective point of view. Progress rooted in collective influence theory, belief-propagation and computer science will be presented. Finally, we present some applications of influencer identification in diverse real-world systems, including online social platforms, scientific publication, brain networks and socioeconomic systems.Comment: 24 pages, 6 figure

    Biology of the red mullet mullus surmuletus (mullidae) off the Canary Islands, Central-East Atlantic

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    The biology of red mullet Mullus surmuletus was studied from collections taken off the Canary Islandsbetween January 1991 and September 1993. Total length ranged from 12 to 33 cm, mainly between 15 and 21cm. Males ranged from 14 to 26 cm and females from 14 to 33 cm. Females dominated the larger size-classes (>18 cm). The overall ratio of males to females was 1:2.3. The reproductive period extended from February toMay, spawning peaking in March and April. The total length at 50% maturity was 16.6 cm for the whole population.The length-mass relationship for all individuals can be described by the parameters a = 0.0074 and b = 3.1826. Fish aged 0.8 years were present in the samples. The parameters of the Von Bertalanffy growth equation obtained for all individuals were: L‡ = 35.71 cm and k = 0.22.year-1. Significant differences were found in the growth parameters between males and females. The rates of total mortality Z, natural mortality M and fishing mortality F were 1.25, 0.55 and 0.70.year-1 respectively. The estimated total length at first capture was 15.74 cm

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    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 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

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Polar Spinel-Perovskite Interfaces: an atomistic study of Fe3O4(111)/SrTiO3(111) structure and functionality

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    Atomic resolution scanning transmission electron microscopy and electron energy loss spectroscopy combined with ab initio electronic calculations are used to determine the structure and properties of the Fe3O4(111)/SrTiO3(111) polar interface. The interfacial structure and chemical composition are shown to be atomically sharp and of an octahedral Fe/SrO3 nature. Band alignment across the interface pins the Fermi level in the vicinity of the conduction band of SrTiO3. Density functional theory calculations demonstrate very high spin-polarization of Fe3O4 in the interface vicinity which suggests that this system may be an excellent candidate for spintronic applications
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