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When adolescents stop psychological therapy: rupture-repair in the therapeutic alliance and association with therapy ending
therapeutic alliance consistently predicts dropout from psychological therapy, and ruptures in the therapeutic alliance may also predict dropout, yet there is a dearth
of research with adolescents. This study investigated whether markers of rupturerepair in the therapeutic alliance were indicative of different types of treatment ending in adolescents who received psychological treatment for depression. Data were from the IMPACT study, a trial investigating the effectiveness of therapies for adolescent depression. Participants were randomly allocated to receive a psychological therapy: Brief Psychosocial Intervention, Cognitive-Behavioural Therapy or Short-Term Psychoanalytic Psychotherapy. The sample (N=35) comprised adolescents who had either completed their treatment (n=14) or dropped out (n=21) according to their therapist. Dropout cases were further classified as dissatisfied (n=14) or got-whatthey-
needed (n=7) based on post-therapy interviews with the adolescent and therapist. Selected audio-recordings of therapy sessions were rated using the Rupture Resolution Rating System and Working Alliance Inventory (observer-version). Therapeutic alliance and rupture-repair during therapy were similar for completers and got-what-they-needed dropouts, while dissatisfied dropouts had poorer
therapeutic alliance, more ruptures, ruptures were frequently unresolved, and therapists contributed to ruptures to a greater extent. Qualitative analysis of the sessions led to the construction of three categories of therapist contribution to
ruptures: therapist minimal response; persisting with a therapeutic activity; and focus on risk. Results suggest that ruptures, especially when unresolved, could be regarded
as warning signs of disengagement and dropout from psychological treatment. Future research should investigate how ruptures may be effectively identified and resolved in
treatment with adolescents
Energy spectrum, dissipation and spatial structures in reduced Hall magnetohydrodynamic
We analyze the effect of the Hall term in the magnetohydrodynamic turbulence
under a strong externally supported magnetic field, seeing how this changes the
energy cascade, the characteristic scales of the flow and the dynamics of
global magnitudes, with particular interest in the dissipation.
Numerical simulations of freely evolving three-dimensional reduced
magnetohydrodynamics (RHMHD) are performed, for different values of the Hall
parameter (the ratio of the ion skin depth to the macroscopic scale of the
turbulence) controlling the impact of the Hall term. The Hall effect modifies
the transfer of energy across scales, slowing down the transfer of energy from
the large scales up to the Hall scale (ion skin depth) and carrying faster the
energy from the Hall scale to smaller scales. The final outcome is an effective
shift of the dissipation scale to larger scales but also a development of
smaller scales. Current sheets (fundamental structures for energy dissipation)
are affected in two ways by increasing the Hall effect, with a widening but at
the same time generating an internal structure within them. In the case where
the Hall term is sufficiently intense, the current sheet is fully delocalized.
The effect appears to reduce impulsive effects in the flow, making it less
intermittent.Comment: 17 pages, 10 figure
Effects of electron inertia in collisionless magnetic reconnection
We present a study of collisionless magnetic reconnection within the
framework of full two-fluid MHD for a completely ionized hydrogen plasma,
retaining the effects of the Hall current, electron pressure and electron
inertia. We performed 2.5D simulations using a pseudo-spectral code with no
dissipative effects. We check that the ideal invariants of the problem are
conserved down to round-off errors. Our results show that the change in the
topology of the magnetic field lines is exclusively due to the presence of
electron inertia. The computed reconnection rates remain a fair fraction of the
Alfv\'en velocity, which therefore qualifies as fast reconnection
Intermittency in Hall-magnetohydrodynamics with a strong guide field
We present a detailed study of intermittency in the velocity and magnetic
field fluctuations of compressible Hall-magnetohydrodynamic turbulence with an
external guide field. To solve the equations numerically, a reduced model valid
when a strong guide field is present is used. Different values for the ion skin
depth are considered in the simulations. The resulting data is analyzed
computing field increments in several directions perpendicular to the guide
field, and building structure functions and probability density functions. In
the magnetohydrodynamic limit we recover the usual results with the magnetic
field being more intermittent than the velocity field. In the presence of the
Hall effect, field fluctuations at scales smaller than the ion skin depth show
a substantial decrease in the level of intermittency, with close to monofractal
scaling.Comment: 10 pages, 8 figure
Interface states and anomalous quantum oscillations in graphene hybrid structures
One- and two-layer graphene have recently been shown to feature new physical
phenomena such as unconventional quantum Hall effects and prospects of
supporting a non-silicon technological platform using epitaxial graphene. While
both one- and two-layer graphene have been studied extensively, continuous
sheets of graphene possessing both parts have not yet been explored. Here we
report a study of such graphene hybrid structures. In a bulk hybrid featuring
two large-area one- and two-layer graphene and an interface between them, two
sets of Landau levels and features related to the interface were found. In edge
hybrids featuring a large two-layer graphene with narrow one-layer graphene
edges, we observed an anomalous suppression in quantum oscillation amplitude
due to the locking of one- and two-layer graphene Fermi energies and emergent
chiral interface states. These findings demonstrate the importance of these
hybrid structures whose unique interface states and related phenomena deserve
further studies.Comment: 4 pages, 4 figure
On Lorentz-Violating Supersymmetric Quantum Field Theories
We study the possibility of constructing Lorentz-violating supersymmetric
quantum field theories under the assumption that these theories have to be
described by lagrangians which are renormalizable by weighted power counting.
Our investigation starts from the observation that at high energies
Lorentz-violation and the usual supersymmetry algebra are algebraically
compatible. Demanding linearity of the supercharges we see that the requirement
of renormalizability drastically restricts the set of possible
Lorentz-violating supersymmetric theories. In particular, in the case of
supersymmetric gauge theories the weighted power counting has to coincide with
the usual one and the only Lorentz-violating operators are introduced by some
weighted constant c that explicitly appears in the supersymmetry algebra. This
parameter does not renormalize and has to be very close to the speed of light
at low energies in order to satisfy the strict experimental bounds on Lorentz
violation. The only possible models with non trivial Lorentz-violating
operators involve neutral chiral superfields and do not have a gauge invariant
extension. We conclude that, under the assumption that high-energy physics can
be described by a renormalizable Lorentz-violating extensions of the Standard
Model, the Lorentz fine tuning problem does not seem solvable by the
requirement of supersymmetry.Comment: 22 pages, 2 figure
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