3,011 research outputs found
Group psychoeducative cognitive-behaviour therapy for mixed anxiety and depression with older adults
Objectives: There is a dearth of older adult evidence regarding the group treatment for co-morbid anxiety and depression. This research evaluated the effectiveness of a low-intensity group psychoeducational approach.
Method: Patients attended six sessions of a manualised cognitive-behavioural group. Validated measures of anxiety, depression and psychological well-being were taken at assessment, termination and six-week follow-up from patients, who also rated the alliance and their anxiety/depression at each group session. Staff rated patients regarding their functioning at assessment, termination and six-week follow-up. Outcomes were categorised according to whether patients had recovered, improved, deteriorated or been harmed. Effect sizes were compared to extant group interventions for anxiety and depression.
Results: Eight groups were completed with 34 patients, with a drop-out rate of 17%. Staff and patient rated outcome measures showed significant improvements (with small effect sizes) in assessment to termination and assessment to follow-up comparisons. Over one quarter (26.47%) of patients met the recovery criteria at follow-up and no patients were harmed. Outcomes for anxiety were better than for depression with the alliance in groups stable over time.
Conclusion: The intervention evaluated shows clinical and organisational promise. The group approach needs to be further developed and tested in research with greater methodological control
Therapist effects and IAPT Psychological Wellbeing Practitioners (PWPs): A multilevel modelling and mixed methods analysis
The aim of this research was (a) to determine the extent of therapist effects in Psychological Wellbeing Practitioners (PWPs) delivering guided self-help in IAPT services and (b) to identify factors that defined effective PWP clinical practice. Using patient (N = 1122) anxiety and depression outcomes (PHQ-9 and GAD-7), the effectiveness of N = 21 PWPs across 6 service sites was examined using multi-level modelling. PWPs and their clinical supervisors were also interviewed and completed measures of ego strength, intuition and resilience. Therapist effects accounted for around 9 per cent of the variance in patient outcomes. One PWP had significantly better than average outcomes on both PHQ-9 and GAD-7 while 3 PWPs were significantly below average on the PHQ-9 and 2 were below average on the GAD-7. Computed PWP ranks identified quartile clusters of the most (N = 5) and least (N = 5) effective PWPs. More effective PWPs generated higher rates of reliable and clinically significant change and displayed greater resilience, organisational abilities, knowledge and confidence. Study weaknesses are identified and methodological considerations for future studies examining therapist effects in low intensity cognitive behaviour therapy are provided
Rydberg Wave Packets are Squeezed States
We point out that Rydberg wave packets (and similar ``coherent" molecular
packets) are, in general, squeezed states, rather than the more elementary
coherent states. This observation allows a more intuitive understanding of
their properties; e.g., their revivals.Comment: 7 pages of text plus one figure available in the literature, LA-UR
93-2804, to be published in Quantum Optics, LaTe
Exact results for `bouncing' Gaussian wave packets
We consider time-dependent Gaussian wave packet solutions of the Schrodinger
equation (with arbitrary initial central position, x_0, and momentum, p_0, for
an otherwise free-particle, but with an infinite wall at x=0, so-called
bouncing wave packets. We show how difference or mirror solutions of the form
psi(x,t)-psi(-x,t) can, in this case, be normalized exactly, allowing for the
evaluation of a number of time-dependent expectation values and other
quantities in closed form. For example, we calculate _t explicitly which
illustrates how the free-particle kinetic (and hence total) energy is affected
by the presence of the distant boundary. We also discuss the time dependence of
the expectation values of position, _t, and momentum, _t, and their
relation to the impulsive force during the `collision' with the wall. Finally,
the x_0,p_0 --> 0 limit is shown to reduce to a special case of a non-standard
free-particle Gaussian solution. The addition of this example to the literature
then expands on the relatively small number of Gaussian solutions to quantum
mechanical problems with familiar classical analogs (free particle, uniform
acceleration, harmonic oscillator, unstable oscillator, and uniform magnetic
field) available in closed form.Comment: 14 pages, 1 embedded .eps figur
The Stark effect in linear potentials
We examine the Stark effect (the second-order shift in the energy spectrum
due to an external constant force) for two 1-dimensional model quantum
mechanical systems described by linear potentials, the so-called quantum
bouncer (defined by V(z) = Fz for z>0 and V(z) infinite for z<0) and the
symmetric linear potential (given by V(z) = F|z|). We show how straightforward
use of the most obvious properties of the Airy function solutions and simple
Taylor expansions give closed form results for the Stark shifts in both
systems. These exact results are then compared to other approximation
techniques, such as perturbation theory and WKB methods. These expressions add
to the small number of closed-form descriptions available for the Stark effect
in model quantum mechanical systems.Comment: 15 pages. To appear in Eur. J. Phys. Needs Institute of Physics
(iopart) style file
A systematic review of therapist effects: A critical narrative update and refinement to Baldwin and Imel's (2013) review
Objective: To review the therapist effects literature since Baldwin and Imel's (2013) review.
Method: Systematic literature review of three databases (PsycINFO, PubMed and Web of Science) replicating Baldwin and Imel (2013) search terms. Weighted averages of therapist effects (TEs) were calculated, and a critical narrative review of included studies conducted.
Results: Twenty studies met inclusion criteria (3 RCTs; 17 practice-based) with 19 studies using multilevel modeling. TEs were found in 19 studies. The TE range for all studies was 0.2% to 29% (weighted average = 5%). For RCTs, 1%–29% (weighted average = 8.2%). For practice-based studies, 0.2–21% (weighted average = 5%). The university counseling subsample yielded a lower TE (2.4%) than in other groupings (i.e., primary care, mixed clinical settings, and specialist/focused settings). Therapist sample sizes remained lower than recommended, and few studies appeared to be designed specifically as TE studies as opposed to maximising on the availability of large routine patient datasets.
Conclusions: Therapist effects are a robust phenomenon although considerable heterogeneity exists across studies. Patient severity appeared related to TE size. TEs from RCTs were highly variable. Using an overall therapist effects statistic may lack precision, and TEs might be better reported separately for specific clinical settings
Strange Decays of Nonstrange Baryons
The strong decays of excited nonstrange baryons into the final states Lambda
K, Sigma K, and for the first time into Lambda(1405) K, Lambda(1520) K,
Sigma(1385) K, Lambda K*, and Sigma K*, are examined in a relativized quark
pair creation model. The wave functions and parameters of the model are fixed
by previous calculations of N pi and N pi pi, etc., decays. Our results show
that it should be possible to discover several new negative parity excited
baryons and confirm the discovery of several others by analyzing these final
states in kaon production experiments. We also establish clear predictions for
the relative strengths of certain states to decay to Lambda(1405) K and
Lambda(1520) K, which can be tested to determine if a three-quark model of the
Lambda(1405) K is valid. Our results compare favorably with the results of
partial wave analyses of the limited existing data for the Lambda K and Sigma K
channels. We do not find large Sigma K decay amplitudes for a substantial group
of predicted and weakly established negative-parity states, in contrast to the
only previous work to consider decays of these states into the strange final
states Lambda K and Sigma K.Comment: 25 pages, 8 figures, RevTe
Eikonal analysis of Coulomb distortion in quasi-elastic electron scattering
An eikonal expansion is used to provide systematic corrections to the eikonal
approximation through order , where is the wave number. Electron
wave functions are obtained for the Dirac equation with a Coulomb potential.
They are used to investigate distorted-wave matrix elements for quasi-elastic
electron scattering from a nucleus. A form of effective-momentum approximation
is obtained using trajectory-dependent eikonal phases and focusing factors.
Fixing the Coulomb distortion effects at the center of the nucleus, the
often-used ema approximation is recovered. Comparisons of these approximations
are made with full calculations using the electron eikonal wave functions. The
ema results are found to agree well with the full calculations.Comment: 12 pages, 6 Postscript figure
Analytic results for Gaussian wave packets in four model systems: I. Visualization of the kinetic energy
Using Gaussian wave packet solutions, we examine how the kinetic energy is
distributed in time-dependent solutions of the Schrodinger equation
corresponding to the cases of a free particle, a particle undergoing uniform
acceleration, a particle in a harmonic oscillator potential, and a system
corresponding to an unstable equilibrium. We find, for specific choices of
initial parameters, that as much as 90% of the kinetic energy can be localized
(at least conceptually) in the `front half' of such Gaussian wave packets, and
we visualize these effects.Comment: 22 pages, RevTeX, four .eps figures, to appear in Found. Phys. Lett.
Vol. 17, Dec. 200
Weak localization of light by cold atoms: the impact of quantum internal structure
Since the work of Anderson on localization, interference effects for the
propagation of a wave in the presence of disorder have been extensively
studied, as exemplified in coherent backscattering (CBS) of light. In the
multiple scattering of light by a disordered sample of thermal atoms,
interference effects are usually washed out by the fast atomic motion. This is
no longer true for cold atoms where CBS has recently been observed. However,
the internal structure of the atoms strongly influences the interference
properties. In this paper, we consider light scattering by an atomic dipole
transition with arbitrary degeneracy and study its impact on coherent
backscattering. We show that the interference contrast is strongly reduced.
Assuming a uniform statistical distribution over internal degrees of freedom,
we compute analytically the single and double scattering contributions to the
intensity in the weak localization regime. The so-called ladder and crossed
diagrams are generalized to the case of atoms and permit to calculate
enhancement factors and backscattering intensity profiles for polarized light
and any closed atomic dipole transition.Comment: 22 pages Revtex, 9 figures, to appear in PR
- …