1,633 research outputs found

    Election Law and Government Ethics

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    This article surveys developments in Virginia election and government ethics laws for 2014 and 2015, with an emphasis on legislative developments. The focus is on those statutory developments thathave significance or general applicability to the implementation of Virginia\u27s election and ethics laws

    A Variational Principle Based Study of KPP Minimal Front Speeds in Random Shears

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    Variational principle for Kolmogorov-Petrovsky-Piskunov (KPP) minimal front speeds provides an efficient tool for statistical speed analysis, as well as a fast and accurate method for speed computation. A variational principle based analysis is carried out on the ensemble of KPP speeds through spatially stationary random shear flows inside infinite channel domains. In the regime of small root mean square (rms) shear amplitude, the enhancement of the ensemble averaged KPP front speeds is proved to obey the quadratic law under certain shear moment conditions. Similarly, in the large rms amplitude regime, the enhancement follows the linear law. In particular, both laws hold for the Ornstein-Uhlenbeck process in case of two dimensional channels. An asymptotic ensemble averaged speed formula is derived in the small rms regime and is explicit in case of the Ornstein-Uhlenbeck process of the shear. Variational principle based computation agrees with these analytical findings, and allows further study on the speed enhancement distributions as well as the dependence of enhancement on the shear covariance. Direct simulations in the small rms regime suggest quadratic speed enhancement law for non-KPP nonlinearities.Comment: 28 pages, 14 figures update: fixed typos, refined estimates in section

    Anomalous Electron Transport in Field-Effect Transistors with Titanium Ditelluride Semimetal Thin-Film Channels

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    We report on "graphene-like" mechanical exfoliation of thin films of titanium ditelluride and investigation of their electronic properties. The exfoliated crystalline TiTe2 films were used as the channel layers in the back-gated field-effect transistors fabricated with Ti/Al/Au metal contacts on SiO2/Si substrates. The room-temperature current-voltage characteristics revealed strongly non-linear behavior with signatures of the source-drain threshold voltage similar to those observed in the charge-density-wave devices. The drain-current showed an unusual non-monotonic dependence on the gate bias characterized by the presence of multiple peaks. The obtained results can be potentially used for implementation of the non-Boolean logic gates.Comment: 11 pages, 4 figure

    The effects of cognitive-behavioural therapy on mood-related ruminative response style in depressed adolescents

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    <p>Abstract</p> <p>Background</p> <p>A mood-related ruminative response style increases the risk of onset and persistence of depression. This preliminary study investigated whether, in depressed adolescents, cognitive-behaviour therapy reduces mood-related ruminative response style. Whether specific factors within the rumination scale were differentially affected by CBT is also reported.</p> <p>Methods</p> <p>26 depressed adolescents were randomised to receiving serotonin-specific reuptake inhibitor antidepressants (SSRI) plus psychosocial treatment as usual or SSRI and psychosocial treatment as usual plus CBT. Ruminative response style and depressive symptoms were measured at baseline and after 30 weeks of treatment, with the Responses to Depression Questionnaire and Mood and Feelings Questionnaire.</p> <p>Results</p> <p>There were significantly greater reductions in ruminations in the CBT group compared to the non-CBT group (<it>p </it>= .002). There was no significant difference in the reduction in self-reported depressive symptoms between the groups. Rumination was reduced to levels of never-depressed controls in adolescents who had recovered from depression and received CBT. There were greater falls in the CBT group in the more pathological 'brooding' factor of rumination.</p> <p>Conclusion</p> <p>These findings suggest that adding CBT to SSRI medication in the presence of active clinical care causes a greater reduction in mood-related ruminative response style in depressed adolescents. This may reduce the risk of future relapse.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCNT83809224.</p

    Coulomb Energy of Nuclei

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    The density functional determining the Coulomb energy of nuclei is calculated to the first order in e2e^2. It is shown that the Coulomb energy includes three terms: the Hartree energy; the Fock energy; and the correlation Coulomb energy (CCE), which contributes considerably to the surface energy, the mass difference between mirror nuclei, and the single-particle spectrum. A CCE-based mechanism of a systematic shift of the single-particle spectrum is proposed. A dominant contribution to the CCE is shown to come from the surface region of nuclei. The CCE effect on the calculated proton drip line is examined, and the maximum charge ZZ of nuclei near this line is found to decrease by 2 or 3 units. The effect of Coulomb interaction on the effective proton mass is analyzed.Comment: 10 pages, Latex. Devoted to 90-th Anniversary of A.B. Migdal's Birthda

    Detecting depression in dyadic conversations with multimodal narratives and visualizations

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    Conversations contain a wide spectrum of multimodal information that gives us hints about the emotions and moods of the speaker. In this paper, we developed a system that supports humans to analyze conversations. Our main contribution is the identification of appropriate multimodal features and the integration of such features into verbatim conversation transcripts. We demonstrate the ability of our system to take in a wide range of multimodal information and automatically generated a prediction score for the depression state of the individual. Our experiments showed that this approach yielded better performance than the baseline model. Furthermore, the multimodal narrative approach makes it easy to integrate learnings from other disciplines, such as conversational analysis and psychology. Lastly, this interdisciplinary and automated approach is a step towards emulating how practitioners record the course of treatment as well as emulating how conversational analysts have been analyzing conversations by hand.Comment: 12 page

    Survey of charge symmetry breaking operators for dd -> alpha pi0

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    The charge-symmetry-breaking amplitudes for the recently observed d d -> alpha pi0 reaction are investigated. Chiral perturbation theory is used to classify and identify the leading-order terms. Specific forms of the related one- and two-body tree level diagrams are derived. As a first step toward a full calculation, a few tree-level two-body diagrams are evaluated at each considered order, using a simplified set of d and alpha wave functions and a plane-wave approximation for the initial dd state. The leading-order pion-exchange term is shown to be suppressed in this model because of poor overlap of the initial and final states. The higher-order one-body and short-range (heavy-meson-exchange) amplitudes provide better matching between the initial and final states and therefore contribute significantly and coherently to the cross section. The consequences this might have for a full calculation, with realistic wave functions and a more complete set of amplitudes, are discussed.Comment: REVTeX 4, 35 pages, 8 eps figures, submitted to PR

    Last passage percolation and traveling fronts

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    We consider a system of N particles with a stochastic dynamics introduced by Brunet and Derrida. The particles can be interpreted as last passage times in directed percolation on {1,...,N} of mean-field type. The particles remain grouped and move like a traveling wave, subject to discretization and driven by a random noise. As N increases, we obtain estimates for the speed of the front and its profile, for different laws of the driving noise. The Gumbel distribution plays a central role for the particle jumps, and we show that the scaling limit is a L\'evy process in this case. The case of bounded jumps yields a completely different behavior

    The Off Shell ρ\rho-ω\omega Mixing in the QCD Sum Rules

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    The q2q^2 dependence of the ρω\rho-\omega mixing amplitude is analyzed with the use of the QCD sum rules and the dispersion relation. Going off shell the mixing decreases, changes sign at q20.4mρ2>0q^2 \simeq 0.4 m_{\rho}^2 > 0 and is negative in the space like region. Implications of this result to the isospin breaking part of the nuclear force are discussed.Comment: 26 pages + 11 figures (PostScript
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