Enhancing Social Connectedness in Anxiety and Depression Through Amplification of Positivity: Preliminary Treatment Outcomes and Process of Change.

BackgroundAnxiety and depressive disorders are often characterized by perceived social disconnection, yet evidence-based treatments produce only modest improvements in this domain. The well-established link between positive affect (PA) and social connectedness suggests that directly targeting PA in treatment may be valuable.MethodA secondary analysis of a waitlist-controlled trial (N=29) was conducted to evaluate treatment response and process of change in social connectedness within a 10-session positive activity intervention protocol-Amplification of Positivity (AMP)-designed to increase PA in individuals seeking treatment for anxiety or depression (ClinicalTrials.gov Identifier: NCT02330627). Perceived social connectedness and PA/negative affect (NA) were assessed throughout treatment. Time-lagged multilevel mediation models examined the process of change in affect and connectedness throughout treatment.ResultsThe AMP group displayed significantly larger improvements in social connectedness from pre- to post-treatment compared to waitlist; improvements were maintained through 6-month follow-up. Within the AMP group, increases in PA and decreases in NA both uniquely predicted subsequent increases in connectedness throughout treatment. However, experiencing heightened NA throughout treatment attenuated the effect of changes in PA on connectedness. Improvements in connectedness predicted subsequent increases in PA, but not changes in NA.ConclusionsThese preliminary findings suggest that positive activity interventions may be valuable for enhancing social connectedness in individuals with clinically impairing anxiety or depression, possibly through both increasing positive emotions and decreasing negative emotions

Status report on Corsica modeling for current drive scenario development

This milestone report covers the progress and status of Corsica modeling for DIII-D experiments over the past year, since our previous report in September, 1995. During this time, we have concentrated on improvements to the code in support of our ability to do self-consistent, predictive modeling of DIII-D discharges. Our interest is in obtaining a tool, benchmarked with experimental data, for developing advanced tokamak operations scenarios including simulation and analysis of high performance negative central shear (NCS) discharges and control of the current profile evolution. Our major focus has been on installing and improving the neutral beam current drive mode in Corsica; this element is critical to modeling the evolution of DIII-D discharges. The NFREYA neutral beam deposition code was installed (starting with a version consistent with GA`s ONETWO code) and the capability for following particle orbits, including the effects of drifts, was added for determining the current driven by neutral beam -injection. In addition, improved methods for more easily integrating experimental profile measurements into the code operation and for calculating Z{sub eff} either from models or from impurity density measurements have been added. We have recently begun to turn on various transport models in our simulation of discharge evolution. We have concentrated on the NCS configuration and have simulated the evolution of two different high neutron reactivity discharges; an NCS discharge with L-mode edge and a single- null, weak NCS discharge from the JET/ITER/DIII-D equivalent shape experiments. Corsica simulation results for these discharges were presented at the EPS meeting in Kiev, Ukraine in June, 1996

ITER Shape Controller and Transport Simulations

We currently use the CORSICA integrated modeling code for scenario studies for both the DIII-D and ITER experiments. In these simulations, free- or fixed-boundary equilibria are simultaneously converged with thermal evolution determined from transport models providing temperature and current density profiles. Using a combination of fixed boundary evolution followed by free-boundary calculation to determine the separatrix and coil currents. In the free-boundary calculation, we use the state-space controller representation with transport simulations to provide feedback modeling of shape, vertical stability and profile control. In addition to a tightly coupled calculation with simulator and controller imbedded inside CORSICA, we also use a remote procedure call interface to couple the CORSICA non-linear plasma simulations to the controller environments developed within the Mathworks Matlab/Simulink environment. We present transport simulations using full shape and vertical stability control with evolution of the temperature profiles to provide simulations of the ITER controller and plasma response

Model dependence of single-energy fits to pion photoproduction data

Model dependence of multipole analysis has been explored through energy-dependent and single-energy fits to pion photoproduction data. The MAID energy-dependent solution has been used as input for an event generator producing realistic pseudo data. These were fitted using the SAID parametrization approach to determine single-energy and energy-dependent solutions over a range of lab photon energies from 200 to 1200 MeV. The resulting solutions were found to be consistent with the input amplitudes from MAID. Fits with a $\chi$-squared per datum of unity or less were generally achieved. We discuss energy regions where consistent results are expected, and explore the sensitivity of fits to the number of included single- and double-polarization observables. The influence of Watson's theorem is examined in detail.Comment: 12 pages, 8 figure

Analysis and Modeling of DIII-D Hybrid Discharges and their Extrapolation to ITER

Recent experiments on tokamaks around the world [1-5] have demonstrated discharges with moderately high performance in which the q-profile remains stationary, as measured by the motional Stark effect diagnostic, for periods up to several {tau}{sub R}. Hybrid discharges are characterize by q{sub min} {approx} 1, high {beta}{sub N}, and good confinement. These discharges have been termed hybrid because of their intermediate nature between that of an ordinary H-mode and advanced tokamak discharges. They form an attractive scenario for ITER as the normalized fusion performance ({beta}{sub N}H{sub 89P}/q{sub 95}{sup 2}) is at or above that for the ITER baseline Q{sub fus} = 10 scenario, even for q{sub 95} as high as 4.6. The startup phase is thought to be crucial to the ultimate evolution of the hybrid discharge. An open question is how hybrid discharges achieve and maintain their stationary state during the initial startup phase. To investigate this aspect of hybrid discharges, we have used the CORSICA code to model the early stages of a discharge. Results clearly indicate that neoclassical current evolution alone is insufficient to account for the time evolution of the q-profile and that an addition of non-inductive current source must be incorporated into the model to reproduce the experimental time history. We include non-inductive neutral beam and bootstrap current sources in the model, and investigate the difference between simulations with these sources and the experimentally inferred q-profile. Further, we have made preliminary estimates of the spatial structure of the current needed to bring the simulation and experiment into agreement. This additional non-inductive source has not been tied to any physical mechanism as yet. We present these results and discuss the implications for hybrid startup on ITER

Evidence for Anomalous Effects on the Current Evolution in Tokamak Operating Scenarios

Alternatives to the usual picture of advanced tokamak (AT) discharges are those that form when anomalous effects alter the plasma current and pressure profiles and those that achieve stationary characteristics through mechanisms so that a measure of desired AT features is maintained without external current-profile control. Regimes exhibiting these characteristics are those where the safety factor (q) evolves to a stationary profile with the on-axis and minimum q {approx} 1 and those with a deeply hollow current channel and high values of q. Operating scenarios with high fusion performance at low current and where the inductively driven current density achieves a stationary configuration with either small or non-existing sawteeth may enhance the neutron fluence per pulse on ITER and future burning plasmas. Hollow current profile discharges exhibit high confinement and a strong ''box-like'' internal transport barrier (ITB). We present results providing evidence for current profile formation and evolution exhibiting features consistent with anomalous effects or with self-organizing mechanisms. Determination of the underlying physical processes leading to these anomalous effects is important for scaling of current experiments for application in future burning plasmas