30,114 research outputs found
Psychodynamic therapy: a poorly defined concept with questionable evidence
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 and
We consider lepton-mass effects in the cascade decays and . Since the scale of the problem
is set by the off-shellness of the respective gauge bosons in the
limits and not by
, lepton-mass effects are non-negligible for the 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 mode which, in part, is due
to the fact that the ratio of lepton helicity flip/nonflip contributions in the
decay is four times larger than in the decay
. We also briefly consider the corresponding
off-shell -- off-shell decays and .Comment: 45 pages, 9 figures and 6 tables, published versio
Extremal Optimization: Methods derived from Co-Evolution
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
Published in final edited form as: Psychiatr Clin North Am. 2017 December ; 40(4): 739β749. 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
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
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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