29,872 research outputs found

    Psychodynamic therapy: a poorly defined concept with questionable evidence

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    R34 MH086668 - NIMH NIH HHS; R01 AT007257 - NCCIH NIH HHS; R21 MH101567 - NIMH NIH HHS; R34 MH099311 - NIMH NIH HHS; R21 MH102646 - NIMH NIH HHS; K23 MH100259 - NIMH NIH HHS; R01 MH099021 - NIMH NIH HH

    Lepton-mass effects in the decays Hβ†’ZZβˆ—β†’β„“+β„“βˆ’Ο„+Ο„βˆ’H \to ZZ^{\ast} \to \ell^{+} \ell^{-} \tau^{+} \tau^{-} and Hβ†’WWβˆ—β†’β„“Ξ½Ο„Ξ½Ο„H \to WW^{\ast} \to \ell \nu \tau \nu_{\tau}

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    We consider lepton-mass effects in the cascade decays Hβ†’Z(β†’β„“+β„“βˆ’)+Zβˆ—(β†’Ο„+Ο„βˆ’)H\to Z(\to \ell^{+} \ell^{-})+Z^{\ast}(\to \tau^{+}\tau^{-}) and Hβ†’Wβˆ’(β†’β„“βˆ’Ξ½Λ‰β„“)+W+βˆ—(β†’Ο„+Ξ½Ο„)H\to W^{-}(\to \ell^{-}\bar \nu_{\ell})+W^{+\ast}(\to \tau^{+}\nu_{\tau}). Since the scale of the problem is set by the off-shellness q2q^{2} of the respective gauge bosons in the limits (mβ„“+mβ„“β€²)2≀q2≀(mHβˆ’mW,Z)2(m_{\ell}+m_{\ell'})^{2} \le q^{2} \le (m_{H}-m_{W,Z})^{2} and not by mW,Z2m_{W,Z}^{2}, lepton-mass effects are non-negligible for the Ο„\tau modes in particular close to the threshold of the off-shell decays. Lepton-mass effects show up e.g.\ in the three-fold joint angular decay distribution for the decays. Nonzero lepton masses lead to leptonic helicity-flip contributions which in turn can generate novel angular dependencies in the respective three-fold angular decay distributions. Lepton-mass effects are more pronounced in the Hβ†’Z(β†’β„“β„“)Zβˆ—(→ττ)H \to Z(\to \ell\ell)Z^{\ast}(\to\tau\tau) mode which, in part, is due to the fact that the ratio of lepton helicity flip/nonflip contributions in the decay Zβˆ—β†’β„“+β„“βˆ’Z^{\ast} \to \ell^{+}\ell^{-} is four times larger than in the decay W+βˆ—β†’β„“+Ξ½W^{+\ast}\to \ell^{+}\nu. We also briefly consider the corresponding off-shell -- off-shell decays Hβ†’Zβˆ—(β†’β„“+β„“βˆ’)+Zβˆ—(β†’Ο„+Ο„βˆ’)H\to Z^{\ast}(\to \ell^{+}\ell^{-})+Z^{\ast}(\to \tau^{+}\tau^{-}) and Hβ†’Wβˆ’βˆ—(β†’β„“βˆ’Ξ½Λ‰β„“)+W+βˆ—(β†’Ο„+Ξ½Ο„)H\to W^{-\ast}(\to \ell^{-}\bar \nu_{\ell})+W^{+\ast}(\to \tau^{+}\nu_{\tau}).Comment: 45 pages, 9 figures and 6 tables, published versio

    Extremal Optimization: Methods derived from Co-Evolution

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    We describe a general-purpose method for finding high-quality solutions to hard optimization problems, inspired by self-organized critical models of co-evolution such as the Bak-Sneppen model. The method, called Extremal Optimization, successively eliminates extremely undesirable components of sub-optimal solutions, rather than ``breeding'' better components. In contrast to Genetic Algorithms which operate on an entire ``gene-pool'' of possible solutions, Extremal Optimization improves on a single candidate solution by treating each of its components as species co-evolving according to Darwinian principles. Unlike Simulated Annealing, its non-equilibrium approach effects an algorithm requiring few parameters to tune. With only one adjustable parameter, its performance proves competitive with, and often superior to, more elaborate stochastic optimization procedures. We demonstrate it here on two classic hard optimization problems: graph partitioning and the traveling salesman problem.Comment: 8 pages, Latex, 5 ps-figures included. To appear in ``GECCO-99: Proceedings of the Genetic and Evolutionary Computation Conference,'' (Morgan Kaufmann, San Francisco, 1999

    Mindfulness-based interventions for anxiety and depression

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    Published in final edited form as: Psychiatr Clin North Am. 2017 December ; 40(4): 739–749. doi:10.1016/j.psc.2017.08.008.This article reviews the ways in which mindfulness practices have contributed to cognitive and behavioral treatments for depression and anxiety. Research on mindfulness-based interventions (MBIs) has increased rapidly in the past decade. The most common include mindfulness-based stress reduction and mindfulness-based cognitive therapy. MBIs are effective in reducing anxiety and depression symptom severity in a range of individuals. MBIs consistently outperform non-evidence-based treatments and active control conditions, such as health education, relaxation training, and supportive psychotherapy. MBIs also perform comparably with cognitive behavior therapy (CBT). The treatment principles of MBIs for anxiety and depression are compatible with standard CBT.R01 AT007257 - NCCIH NIH HH

    Short- and Long- Time Transport Structures in a Three Dimensional Time Dependent Flow

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    Lagrangian transport structures for three-dimensional and time-dependent fluid flows are of great interest in numerous applications, particularly for geophysical or oceanic flows. In such flows, chaotic transport and mixing can play important environmental and ecological roles, for examples in pollution spills or plankton migration. In such flows, where simulations or observations are typically available only over a short time, understanding the difference between short-time and long-time transport structures is critical. In this paper, we use a set of classical (i.e. Poincar\'e section, Lyapunov exponent) and alternative (i.e. finite time Lyapunov exponent, Lagrangian coherent structures) tools from dynamical systems theory that analyze chaotic transport both qualitatively and quantitatively. With this set of tools we are able to reveal, identify and highlight differences between short- and long-time transport structures inside a flow composed of a primary horizontal contra-rotating vortex chain, small lateral oscillations and a weak Ekman pumping. The difference is mainly the existence of regular or extremely slowly developing chaotic regions that are only present at short time.Comment: 9 pages, 9 figure

    Numerical solution of scattering problems using a Riemann--Hilbert formulation

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    A fast and accurate numerical method for the solution of scalar and matrix Wiener--Hopf problems is presented. The Wiener--Hopf problems are formulated as Riemann--Hilbert problems on the real line, and a numerical approach developed for these problems is used. It is shown that the known far-field behaviour of the solutions can be exploited to construct numerical schemes providing spectrally accurate results. A number of scalar and matrix Wiener--Hopf problems that generalize the classical Sommerfeld problem of diffraction of plane waves by a semi-infinite plane are solved using the approach
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