1,643 research outputs found

    Hypercyclicity of special operators on Hilbert function spaces

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    summary:In this paper we give some sufficient conditions for the adjoint of a weighted composition operator on a Hilbert space of analytic functions to be hypercyclic

    For fibromyalgia, which treatments are the most effective?

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    There is no single most effective modality for the treatment of fibromyalgia syndrome, and no objective comparison of the results from the different studies is available. Low-dose tricyclic antidepressants (TCAs) improve sleep quality and global well-being and have a moderate beneficial effect on tenderness and stiffness (strength of recommendation [SOR]: A, based on a systematic review of randomized controlled trials [RCTs]). Selective serotonin reuptake inhibitors (SSRIs) may moderately improve fibromyalgia-related symptoms (SOR: B, based on a few RCTs). The serotonin and norepinephrine reuptake inhibitors (SNRIs) duloxetine (Cymbalta) and milnacipran (Ixel, not currently available in the US) improve pain and other symptoms (SOR: B, based on single RCTs). Tramadol (Ultram) improves pain and other outcomes (SOR: A, based on a few RCTs). Cyclobenzaprine (Flexeril) improves both pain and sleep quality (SOR: A, based on a systematic review of RCTs). Aerobic exercise improves overall functional capacity and sense of well-being for patients with fibromyalgia (SOR: A, based on a systematic review of RCT). Cognitive behavioral therapy improves patients' self-reported symptoms (SOR: A, based on RCTs)

    Measurement of net electric charge and dipole moment of dust aggregates in a complex plasma

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    Understanding the agglomeration of dust particles in complex plasmas requires a knowledge of the basic properties such as the net electrostatic charge and dipole moment of the dust. In this study, dust aggregates are formed from gold coated mono-disperse spherical melamine-formaldehyde monomers in a radio-frequency (rf) argon discharge plasma. The behavior of observed dust aggregates is analyzed both by studying the particle trajectories and by employing computer models examining 3D structures of aggregates and their interactions and rotations as induced by torques arising from their dipole moments. These allow the basic characteristics of the dust aggregates, such as the electrostatic charge and dipole moment, to be determined. It is shown that the experimental results support the predicted values from computer models for aggregates in these environments.Comment: 6 pages, 7 figure

    A novel hydrogen peroxide biosensor based on modified electrode with hemoglobin and zinc oxide nanoparticles

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    In this study, direct electron transfer between immobilized hemoglobin (Hb) and zinc oxide nanoparticles modified carbon paste electrode was studied. Direct electrochemical response of Hb on the modified electrode can be achieved and a couple of well-defined and nearly reversible cyclic voltammetric peaks of Hb can be observed in a phosphate solution. The Hb immobilized on the Modified electrode with Zno Nps displayed a pair of redox peaks in 0.1 M pH 7.0 PBS with a formal potential of + (292 ± 2) mV (vs. SCE). Hb adsorbed on the modified electrode surface shows a good activity for the reduction of hydrogen peroxide (H2O2). The reduction peak currents were proportional linearly to the concentration of hydrogen peroxide. The Hb/ Zno Nps/ CPE had good repeatability and stability for the determination of H2O2

    Safely dissolvable and healable active packaging films based on alginate and pectin

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    Extensive usage of long-lasting petroleum based plastics for short-lived application such as packaging has raised concerns regarding their role in environmental pollution. In this research, we have developed active, healable, and safely dissolvable alginate-pectin based biocomposites that have potential applications in food packaging. The morphological study revealed the rough surface of these biocomposite films. Tensile properties indicated that the fabricated samples have mechanical properties in the range of commercially available packaging films while possessing excellent healing effciency. Biocomposite films exhibited higher hydrophobicity properties compared to neat alginate films. Thermal analysis indicated that crosslinked biocomposite samples possess higher thermal stability in temperatures below 120 °C, while antibacterial analysis against E. coli and S. aureus revealed the antibacterial properties of the prepared samples against different bacteria. The fabricated biodegradable multi-functional biocomposite films possess various imperative properties, making them ideal for utilization as packaging material

    Tight Two-Dimensional Outer-Approximations of Feasible Sets in Wireless Sensor Networks

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    Finding a tight ellipsoid that contains the intersection of a finite number of ellipsoids is of interest in positioning applications for wireless sensor networks (WSNs). To this end, we propose a novel geometrical method in 2-dimensional (2-D) space. Specifically, we first find a tight polygon, which contains the desired region and then obtain the tightest ellipse containing the polygon by solving a convex optimization problem. For demonstrating the usefulness of this method, we employ it in a distributed algorithm for elliptical outer-approximation of feasible sets in co-operative WSNs. Through simulations, we show that the proposed method gives a tighter bounding ellipse than conventional methods, while having similar computational cost

    On a Linear Program for Minimum-Weight Triangulation

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    Minimum-weight triangulation (MWT) is NP-hard. It has a polynomial-time constant-factor approximation algorithm, and a variety of effective polynomial- time heuristics that, for many instances, can find the exact MWT. Linear programs (LPs) for MWT are well-studied, but previously no connection was known between any LP and any approximation algorithm or heuristic for MWT. Here we show the first such connections: for an LP formulation due to Dantzig et al. (1985): (i) the integrality gap is bounded by a constant; (ii) given any instance, if the aforementioned heuristics find the MWT, then so does the LP.Comment: To appear in SICOMP. Extended abstract appeared in SODA 201
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