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Targeting hyperarousal: Mantram Repetition Program for PTSD in US veterans.
Background: Hyperarousal appears to play an important role in the development and maintenance of posttraumatic stress disorder (PTSD) symptoms, but current evidence-based treatments appear to address this symptom type less effectively than the other symptom clusters. The Mantram Repetition Program (MRP) is a meditation-based intervention that has previously been shown to improve symptoms of posttraumatic stress disorder (PTSD) and may be especially helpful for hyperarousal. If MRP is an effective tool for decreasing this often treatment-resistant symptom cluster, it may become an important clinical tool. Objective: The goal of this secondary analysis was to examine the effect of the MRP on hyperarousal and other PTSD symptom clusters and to examine hyperarousal as a mediator of treatment response. Method: Secondary analyses were conducted on data from a randomized controlled trial in which Veterans with PTSD (n = 173) were assigned to the MRP or a non-specific psychotherapy control and assessed pre-treatment, post-treatment and 8 weeks after treatment completion. The impact of the interventions on PTSD symptom clusters was examined, and time-lagged hierarchical linear modelling was applied to examine alternative mediation models. Results: All PTSD symptom clusters improved in both treatments. MRP led to greater reductions in hyperarousal at post-treatment (Hedge's g = 0.57) and follow-up (Hedge's g = 0.52), and in numbing at post-treatment (Hedge's g = 0.47). Hyperarousal mediated reductions in the composite of the other PTSD symptom clusters. Although the reverse model was significant as well, the effect was weaker in this direction. Conclusion: Interventions focused on the management of hyperarousal may play an important role in recovery from PTSD. The MRP appears efficacious in reducing hyperarousal, and thereby impacting other PTSD symptom clusters, as one pathway to facilitating recovery
Simulation of underground gravity gradients from stochastic seismic fields
We present results obtained from a finite-element simulation of seismic
displacement fields and of gravity gradients generated by those fields. The
displacement field is constructed by a plane wave model with a 3D isotropic
stochastic field and a 2D fundamental Rayleigh field. The plane wave model
provides an accurate representation of stationary fields from distant sources.
Underground gravity gradients are calculated as acceleration of a free test
mass inside a cavity. The results are discussed in the context of
gravity-gradient noise subtraction in third generation gravitational-wave
detectors. Error analysis with respect to the density of the simulated grid
leads to a derivation of an improved seismometer placement inside a 3D array
which would be used in practice to monitor the seismic field.Comment: 24 pages, 12 figure
Holocene Earthquakes and Late Pleistocene Slip-Rate Estimates on the Wassuk Range Fault Zone, Nevada
The Wassuk Range fault zone is an 80‐km‐long, east‐dipping, high‐angle normal fault that flanks the eastern margin of the Wassuk Range in central Nevada. Observations from two alluvial fan systems truncated by the fault yield information on the vertical slip rate and Holocene earthquake history along the range front. At the apex of the Rose Creek alluvial fan, radiocarbon dating of offset stratigraphy exposed in two fault trenches shows that multiple earthquakes resulted in 7.0 m of vertical offset along the fault since ∼9400 cal B.P. These data yield a Holocene vertical slip rate of 0.7±0.1 mm/yr. The south trench exposure records at least two faulting events since ∼9400 cal B.P., with the most recent displacement postdating ∼2810 cal B.P. The north trench exposure records an ∼1 m offset between ∼610 cal B.P. and A.D. ∼1850, a 1.3‐m minimum offset prior to ∼1460 cal B.P., and one earlier undated earthquake of a similar size. Variations in stratigraphy and limited datable material preclude a unique correlation of paleoevents between the two trenches. Approximately 25 km north, the range‐front fault has truncated and uplifted a remnant of the Penrod Canyon fan by \u3e40 m since the surface was deposited ∼113 ka, based on cosmogenic dating of two large boulders. These data allow an estimate of the minimum late Pleistocene vertical slip rate at \u3e0.3–0.4 mm/yr for the Wassuk Range fault zone
Holocene Earthquakes and Late Pleistocene Slip Rate Estimates on the Wassuk Range Fault Zone, Nevada, USA
The Wassuk Range fault zone is an 80‐km‐long, east‐dipping, high‐angle normal fault that flanks the eastern margin of the Wassuk Range in central Nevada. Observations from two alluvial fan systems truncated by the fault yield information on the vertical slip rate and Holocene earthquake history along the range front. At the apex of the Rose Creek alluvial fan, radiocarbon dating of offset stratigraphy exposed in two fault trenches shows that multiple earthquakes resulted in 7.0 m of vertical offset along the fault since ∼9400 cal B.P. These data yield a Holocene vertical slip rate of 0.7±0.1 mm/yr. The south trench exposure records at least two faulting events since ∼9400 cal B.P., with the most recent displacement postdating ∼2810 cal B.P. The north trench exposure records an ∼1 m offset between ∼610 cal B.P. and A.D. ∼1850, a 1.3‐m minimum offset prior to ∼1460 cal B.P., and one earlier undated earthquake of a similar size. Variations in stratigraphy and limited datable material preclude a unique correlation of paleoevents between the two trenches. Approximately 25 km north, the range‐front fault has truncated and uplifted a remnant of the Penrod Canyon fan by \u3e40 m since the surface was deposited ∼113 ka, based on cosmogenic dating of two large boulders. These data allow an estimate of the minimum late Pleistocene vertical slip rate at \u3e0.3–0.4 mm/yr for the Wassuk Range fault zone
Hard and soft probe - medium interactions in a 3D hydro+micro approach at RHIC
We utilize a 3D hybrid hydro+micro model for a comprehensive and consistent
description of soft and hard particle production in ultra-relativistic
heavy-ion collisions at RHIC. In the soft sector we focus on the dynamics of
(multi-)strange baryons, where a clear strangeness dependence of their
collision rates and freeze-out is observed. In the hard sector we study the
radiative energy loss of hard partons in a soft medium in the multiple soft
scattering approximation. While the nuclear suppression factor does
not reflect the high quality of the medium description (except in a reduced
systematic uncertainty in extracting the quenching power of the medium), the
hydrodynamical model also allows to study different centralities and in
particular the angular variation of with respect to the reaction
plane, allowing for a controlled variation of the in-medium path-length.Comment: 5 pages, 4 figures, Quark Matter 2006 proceedings, to appear in
Journal of Physics
Estimation of properties of low-lying excited states of Hubbard models : a multi-configurational symmetrized projector quantum Monte Carlo approach
We present in detail the recently developed multi-configurational symmetrized
projector quantum Monte Carlo (MSPQMC) method for excited states of the Hubbard
model. We describe the implementation of the Monte Carlo method for a
multi-configurational trial wavefunction. We give a detailed discussion of
issues related to the symmetry of the projection procedure which validates our
Monte Carlo procedure for excited states and leads naturally to the idea of
symmetrized sampling for correlation functions, developed earlier in the
context of ground state simulations. It also leads to three possible averaging
schemes. We have analyzed the errors incurred in these various averaging
procedures and discuss and detail the preferred averaging procedure for
correlations that do not have the full symmetry of the Hamiltonian. We study
the energies and correlation functions of the low-lying excited states of the
half-filled Hubbard model in 1-D. We have used this technique to study the
pair-binding energies of two holes in and systems, which compare
well the Bethe ansatz data of Fye, Martins and Scalettar. We have also studied
small clusters amenable to exact diagonalization studies in 2-D and have
reproduced their energies and correlation functions by the MSPQMC method. We
identify two ways in which a multiconfigurational trial wavefunction can lead
to a negative sign problem. We observe that this effect is not severe in 1-D
and tends to vanish with increasing system size. We also note that this does
not enhance the severity of the sign problem in two dimensions.Comment: 29 pages, 2 figures available on request, submitted to Phys. Rev.
Phase Transitions Driven by Vortices in 2D Superfluids and Superconductors: From Kosterlitz-Thouless to 1st Order
The Landau-Ginzburg-Wilson hamiltonian is studied for different values of the
parameter which multiplies the quartic term (it turns out that this
is equivalent to consider different values of the coherence length in
units of the lattice spacing ). It is observed that amplitude fluctuations
can change dramatically the nature of the phase transition: for small values of
(), instead of the smooth Kosterlitz-Thouless transition
there is a {\em first order} transition with a discontinuous jump in the vortex
density and a larger non-universal drop in the helicity modulus. In
particular, for sufficiently small (), the density of
bound pairs of vortex-antivortex below is so low that, drops to zero
almost for all temperature .Comment: 8 pages, 5 .eps figure
Charge Transport in the Dense Two-Dimensional Coulomb Gas
The dynamics of a globally neutral system of diffusing Coulomb charges in two
dimensions, driven by an applied electric field, is studied in a wide
temperature range around the Berezinskii-Kosterlitz-Thouless transition. I
argue that the commonly accepted ``free particle drift'' mechanism of charge
transport in this system is limited to relatively low particle densities. For
higher densities, I propose a modified picture involving collective ``partner
transfer'' between bound pairs. The new picture provides a natural explanation
for recent experimental and numerical findings which deviate from standard
theory. It also clarifies the origin of dynamical scaling in this context.Comment: 4 pages, RevTeX, 2 eps figures included; some typos corrected, final
version to be published in Phys. Rev. Let
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