28,155 research outputs found

    Maximally entangled mixed states: Creation and concentration

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    Using correlated photons from parametric downconversion, we extend the boundaries of experimentally accessible two-qubit Hilbert space. Specifically, we have created and characterized maximally entangled mixed states (MEMS) that lie above the Werner boundary in the linear entropy-tangle plane. In addition, we demonstrate that such states can be efficiently concentrated, simultaneously increasing both the purity and the degree of entanglement. We investigate a previously unsuspected sensitivity imbalance in common state measures, i.e., the tangle, linear entropy, and fidelity.Comment: 4 pages, 3 figures, 1 table; accepted versio

    Maternal cell-free DNA-based screening for fetal microdeletion and the importance of careful diagnostic follow-up.

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    BackgroundNoninvasive prenatal screening (NIPS) by next-generation sequencing of cell-free DNA (cfDNA) in maternal plasma is used to screen for common aneuploidies such as trisomy 21 in high risk pregnancies. NIPS can identify fetal genomic microdeletions; however, sensitivity and specificity have not been systematically evaluated. Commercial companies have begun to offer expanded panels including screening for common microdeletion syndromes such as 22q11.2 deletion (DiGeorge syndrome) without reporting the genomic coordinates or whether the deletion is maternal or fetal. Here we describe a phenotypically normal mother and fetus who tested positive for atypical 22q deletion via maternal plasma cfDNA testing.MethodsWe performed cfDNA sequencing on saved maternal plasma obtained at 11 weeks of gestation from a phenotypically normal woman with a singleton pregnancy whose earlier screening at a commercial laboratory was reported to be positive for a 22q11.2 microdeletion. Fluorescence in situ hybridization and chromosomal microarray diagnostic genetic tests were done postnatally.ConclusionNIPS detected a 22q microdeletion that, upon diagnostic workup, did not include the DiGeorge critical region. Diagnostic prenatal or postnatal testing with chromosomal microarray and appropriate parental studies to determine precise genomic coordinates and inheritance should follow a positive microdeletion NIPS result

    Composite Indices as International Approaches to Elderly Population Well-being Evaluation: Evidence from Russia

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    Population ageing is a natural process with irreversible consequences. Therefore, it has become an important agenda for economic and social policy. It requires the development and practical implementation of new tools for the integrated assessment of the main aspects of the elderly generation economic and social well-being. We account for over 50 years of active academic research work in the area of ​​enhanced elderly population’s well-being assessment as a complex socio-economic phenomenon. The phenomenon may comprise a number of components for evaluation on the basis of both quantitative objective criteria and qualitative subjective criteria. The paper addresses the question of using composite indices such as the AgeWatch Index and the Active Ageing Index for assessing the well-being of the elderly generation in the Russian Federation. The authors also debate the issue of the availability and comparability of the existing data for the Active Ageing Index calculation for Russia. The scope of the analysis falls within national Russian statistical databases in order to determine the possibility of the correct choice of relevant indicators from the sources available for the AAI calculation according to its original methodology

    Asymptotics for turbulent flame speeds of the viscous G-equation enhanced by cellular and shear flows

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    G-equations are well-known front propagation models in turbulent combustion and describe the front motion law in the form of local normal velocity equal to a constant (laminar speed) plus the normal projection of fluid velocity. In level set formulation, G-equations are Hamilton-Jacobi equations with convex (L1L^1 type) but non-coercive Hamiltonians. Viscous G-equations arise from either numerical approximations or regularizations by small diffusion. The nonlinear eigenvalue Hˉ\bar H from the cell problem of the viscous G-equation can be viewed as an approximation of the inviscid turbulent flame speed sTs_T. An important problem in turbulent combustion theory is to study properties of sTs_T, in particular how sTs_T depends on the flow amplitude AA. In this paper, we will study the behavior of Hˉ=Hˉ(A,d)\bar H=\bar H(A,d) as A+A\to +\infty at any fixed diffusion constant d>0d > 0. For the cellular flow, we show that Hˉ(A,d)O(logA)for all d>0. \bar H(A,d)\leq O(\sqrt {\mathrm {log}A}) \quad \text{for all $d>0$}. Compared with the inviscid G-equation (d=0d=0), the diffusion dramatically slows down the front propagation. For the shear flow, the limit \nit limA+Hˉ(A,d)A=λ(d)>0\lim_{A\to +\infty}{\bar H(A,d)\over A} = \lambda (d) >0 where λ(d)\lambda (d) is strictly decreasing in dd, and has zero derivative at d=0d=0. The linear growth law is also valid for sTs_T of the curvature dependent G-equation in shear flows.Comment: 27 pages. We improve the upper bound from no power growth to square root of log growt

    Mixing and reaction efficiency in closed domains

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    We present a numerical study of mixing and reaction efficiency in closed domains. In particular we focus our attention on laminar flows. In the case of inert transport the mixing properties of the flows strongly depend on the details of the Lagrangian transport. We also study the reaction efficiency. Starting with a little spot of product we compute the time needed to complete the reaction in the container. We found that the reaction efficiency is not strictly related to the mixing properties of the flow. In particular, reaction acts as a "dynamical regulator".Comment: 11 pages, 10 figure

    Rewiring strategies for changing environments

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    A typical pervasive application executes in a changing environment: people, computing resources, software services and network connections come and go continuously. A robust pervasive application needs adapt to this changing context as long as there is an appropriate rewiring strategy that guarantees correct behavior. We combine the MERODE modeling methodology with the ReWiRe framework for creating interactive pervasive applications that can cope with changing environments. The core of our approach is a consistent environment model, which is essential to create (re)configurable context-aware pervasive applications. We aggregate different ontologies that provide the required semantics to describe almost any target environment. We present a case study that shows a interactive pervasive application for media access that incorporates parental control on media content and can migrate between devices. The application builds upon models of the run-time environment represented as system states for dedicated rewiring strategies

    Search for unbound 15Be states in the 3n+12Be channel

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    15Be is expected to have low-lying 3/2+ and 5/2+ states. A first search did not observe the 3/2+ [A. Spyrou et al., Phys. Rev. C 84, 044309 (2011)], however, a resonance in 15Be was populated in a second attempt and determined to be unbound with respect to 14Be by 1.8(1) MeV with a tentative spin-parity assignment of 5/2+ [J. Snyder et al., Phys. Rev. C 88, 031303(R) (2013)]. Search for the predicted 15Be 3/2+ state in the three-neutron decay channel. A two-proton removal reaction from a 55 MeV/u 17C beam was used to populate neutron-unbound states in 15Be. The two-, three-, and four-body decay energies of the 12Be + neutron(s) detected in coincidence were reconstructed using invariant mass spectroscopy. Monte Carlo simulations were performed to extract the resonance and decay properties from the observed spectra. The low-energy regions of the decay energy spectra can be described with the first excited unbound state of 14Be (E_x=1.54 MeV, E_r=0.28 MeV). Including a state in 15Be that decays through the first excited 14Be state slightly improves the fit at higher energies though the cross section is small. A 15Be component is not needed to describe the data. If the 3/2+ state in 15Be is populated, the decay by three-neutron emission through 14Be is weak, less than or equal to 11% up to 4 MeV. In the best fit, 15Be is unbound with respect to 12Be by 1.4 MeV (unbound with respect to $14Be by 2.66 MeV) with a strength of 7%.Comment: 6 pages, 5 figures, accepted in Physical Review

    Flames with chain-branching/chain-breaking kinetics

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    A steady plane flame subject to the chain-branching/chain-breaking kinetics A plus X yields 2X, 2X plus M yields 2P plus M is considered for a certain distinguished limit of parameter values corresponding to fast recombination. Here A is the reactant, X the radical, P the product, and M a third body. The activation energy of the production step is very large, while that of the recombination step is small and taken to be zero. The object is to find the 'laminar-flame eigenvalue' DELTA , representing the burning rate, as a function of r, which is essentially the ratio of the two reaction rates. The response function DELTA (r) is described by numerical integration and by asymptotic analysis for r approaches 0, infinity
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