Interpersonal Behavior in Couple Therapy: Concurrent and Prospective Associations with Depressive Symptoms and Relationship Distress

Objective: This study investigated associations between couples’ interpersonal behavior, depressive symptoms, and relationship distress over the course of couple psychotherapy. Method: After every other session of Integrative Systemic Therapy (M = 13 sessions), N = 100 individuals within 50 couples rated their in-session affiliation and autonomy behavior using the circumplex-based Structural Analysis of Social Behavior Intrex. Concurrent and prospective associations of interpersonal behavior with depressive symptoms and relationship distress were evaluated via multivariate multilevel modeling using the Actor-Partner Interdependence Model. Results: An individual’s hostility, as well as the partner’s hostility, positively predicted an individual’s concurrent depressive symptoms and relationship distress, as well as his or her relationship distress at the following session. Partner hostility during one session predicted an individual’s subsequent depressive symptoms. During sessions in which individuals controlled the partner, and separated themselves from the partner, they reported more concurrent depressive symptoms and relationship distress, and more subsequent relationship distress. When partners separated themselves, individuals reported more concurrent depressive symptoms and relationship distress, and more subsequent relationship distress. Conclusions: Results underscore the importance of couples’ in-session affiliation and autonomy behavior in the treatment of depressive symptoms and relationship distress within couple therapy

Electronic Structure of Dangling Bonds in Amorphous Silicon Studied via a Density-Matrix Functional Method

A structural model of hydrogenated amorphous silicon containing an isolated dangling bond is used to investigate the effects of electron interactions on the electronic level splittings, localization of charge and spin, and fluctuations in charge and spin. These properties are calculated with a recently developed density-matrix correlation-energy functional applied to a generalized Anderson Hamiltonian, consisting of tight-binding one-electron terms parametrizing hydrogenated amorphous silicon plus a local interaction term. The energy level splittings approach an asymptotic value for large values of the electron-interaction parameter U, and for physically relevant values of U are in the range 0.3-0.5 eV. The electron spin is highly localized on the central orbital of the dangling bond while the charge is spread over a larger region surrounding the dangling bond site. These results are consistent with known experimental data and previous density-functional calculations. The spin fluctuations are quite different from those obtained with unrestricted Hartree-Fock theory.Comment: 6 pages, 6 figures, 1 tabl

Autumn Management of Grass-legume Pasture

Duration of autumn grazing may affect the long-term balance of grass and legume in a sward. Effects of early and late autumn closing dates were studied on productivity and morphology of orchardgrass (Dactylis glomerata) and white clover (Trifolium repens) in replicated grazed swards. Early-closed paddocks continued to accumulate herbage during autumn, resulting in greater winter senescence than late-closed paddocks. Spring-cut herbage mass was not affected by autumn management; however, late closing had significantly more clover than early closing. Early-closed paddocks were grass domlnanl, with few relatively large tillers and few clover growing points compared with late-closed paddocks at the end of each grazing season. Late closing resulted in more than twice as many clover growing points as early-closed. Stolon mass was greater, but starch and total non-structural carbohydrate contents were less during autumn in late- than in early-closed paddocks. Improvement in clover growing point density and stolon mass in the late-closed treatment may favour clover persistence in mixed swards

Thermally stimulated H emission and diffusion in hydrogenated amorphous silicon

We report first principles ab initio density functional calculations of hydrogen dynam- ics in hydrogenated amorphous silicon. Thermal motion of the host Si atoms drives H diffusion, as we demonstrate by direct simulation and explain with simple models. Si-Si bond centers and Si ring centers are local energy minima as expected. We also describe a new mechanism for break- ing Si-H bonds to release free atomic H into the network: a fluctuation bond center detachment (FBCD) assisted diffusion. H dynamics in a-Si:H is dominated by structural fluctuations intrinsic to the amorphous phase not present in the crystal.Comment: 4 pages, 5 figures, In press EPL (Jun. 2007

Approximate ab initio calculation of vibrational properties of hydrogenated amorphous silicon with inner voids

We have performed an approximate ab initio calculation of vibrational properties of hydrogenated amorphous silicon (a-Si:H) using a molecular dynamics method. A 216 atom model for pure amorphous silicon (a-Si) has been employed as a starting point for our a-Si:H models with voids that were made by removing a cluster of silicon atoms out of the bulk and terminating the resulting dangling bonds with hydrogens. Our calculation shows that the presence of voids leads to localized low energy (30-50 cm^{-1}) states in the vibrational spectrum of the system. The nature and localization properties of these states are analyzed by various visualization techniques.Comment: 15 pages with 6 PS figures, to appear in PRB in December 199

The spin angular gradient approximation in the density functional theory

A spin angular gradient approximation for the exchange correlation magnetic field in the density functional formalism is proposed. The usage of such corrections leads to a consistent spin dynamical approach beyond the local approximation. The proposed technique does not contain any approximations for the form of potential and can be used in modern full potential band structure methods. The obtained results indicate that the direct 'potential' exchange in 3d magnets is rather small compared to the indirect 'kinetic' exchange, thus justifies the dynamical aspect of the local density approximation in 3d metals

Study of electron-irradiated silicon thin films using transient photocurrent spectroscopy

Electron irradiation of silicon thin films creates localised states, which degrade theiropto-electronic properties. We present a series of transient photocurrent spectroscopy (TPC)measurements on electron-irradiated amorphous and microcrystalline silicon films, annealed atprogressively increasing temperatures. This has enabled localised states associated with bothdangling bonds and conduction band tails to be examined over a wide energy range.Trends inthe evolution of the DOS following electron irradiation followed by isochronal annealing stepsindicate reductions in the deep defect density,which correlate with spin density. We also find asteepening of the conduction band tail slope in amorphous silicon on annealing. Both defectdensity and tail slope may be restored close to as-prepared material values. Earlier CPM dataare re-examined, and a similar trend in the valence band tail slope is indicated. Computersimulations predict that following e-irradiation changes in deep defect density primarily controlsolar cell performance, and will tend to obscure effects related to band tails

Event-based relaxation of continuous disordered systems

A computational approach is presented to obtain energy-minimized structures in glassy materials. This approach, the activation-relaxation technique (ART), achieves its efficiency by focusing on significant changes in the microscopic structure (events). The application of ART is illustrated with two examples: the structure of amorphous silicon, and the structure of Ni80P20, a metallic glass.Comment: 4 pages, revtex, epsf.sty, 3 figure

Spin and charge excitations in incommensurate spin density waves

Collective excitations both for spin- and charge-channels are investigated in incommensurate spin density wave (or stripe) states on two-dimensional Hubbard model. By random phase approximation, the dynamical susceptibility \chi(q,\omega) is calculated for full range of (q,\omega) with including all higher harmonics components. An intricate landscape of the spectra in \chi(q,\omega) is obtained. We discuss the anisotropy of the dispersion cones for spin wave excitations, and for the phason excitation related to the motion of the stripe line. Inelastic neutron experiments on Cr and its alloys and stripe states of underdoped cuprates are proposed

Molecular Spiders in One Dimension

Molecular spiders are synthetic bio-molecular systems which have "legs" made of short single-stranded segments of DNA. Spiders move on a surface covered with single-stranded DNA segments complementary to legs. Different mappings are established between various models of spiders and simple exclusion processes. For spiders with simple gait and varying number of legs we compute the diffusion coefficient; when the hopping is biased we also compute their velocity.Comment: 14 pages, 2 figure