Identification of Coulomb blockade and macroscopic quantum tunneling by noise

The effects of Macroscopic Quantum Tunneling (MQT) and Coulomb Blockade (CB) in Josephson junctions are of considerable significance both for the manifestations of quantum mechanics on the macroscopic scale and potential technological applications. These two complementary effects are shown to be clearly distinguishable from the associated noise spectra. The current noise is determined exactly and a rather sharp crossover between flux noise in the MQT and charge noise in the CB regions is found as the applied voltage is changed. Related results hold for the voltage noise in current-biased junctions.Comment: 6 pages, 3 figures, epl.cls include

Vocal communication in gibbons.

Many non-human primates use vocal communication referentially and also use simple syntax and grammar. However, their comparative vocal repertoires are disappointingly sparse, with many researchers concluding that they have fixed vocal patterns made up of a limited number of discrete units used in a relatively small array of contexts (see McComb & Semple, 2005 for a review). Furthermore, these vocal patterns seem to be innate, under high genetic control with little evidence for vocal learning – something that humans are masters at (Janik & Slater 1997). This leaves us with some questions. Firstly, how did humans become so adept at producing and learning vocal sounds? And, secondly, are there any extant primate species with vocal behaviours that can be directly compared to our own?

Shell Crossing Singularities in Quasi-Spherical Szekeres Models

We investigate the occurrence of shell crossing singularities in quasi-spherical Szekeres dust models with or without a cosmological constant. We study the conditions for shell crossing singularity both from physical and geometrical point of view and they are in agreement.Comment: 10 latex pages, RevTex style, no figure

Meta-analysis of cognitive behaviour therapy and selective serotonin reuptake inhibitors for the treatment of hypochondriasis: Implications for trial design

Background: Classification of hypochondriasis as an obsessive-compulsive and related disorder in the International Classification of Diseases 11th Revision (ICD-11) has generated new heuristics for treatment of this common, chronic and disabling disorder. Standard treatment involves cognitive behaviour therapy (CBT) or selective serotonin reuptake inhibitors (SSRIs), but no meta-analysis has so far considered hypochondriasis as a structured diagnosis or assessed the role of medication. A clearer understanding of the relative effectiveness of these interventions and identification of clinically relevant factors moderating the treatment response is needed for clinical guideline development. Methods: The current systematic review and meta-analysis of interventions for hypochondriasis was preregistered on PROSPERO (CRD42020185768) and follows PRISMA guidelines. We searched MEDLINE, PsycINFO, and Cochrane Library databases until July 2021 for randomized controlled trials (RCTs) of interventions for patients diagnosed with hypochondriasis (or historical diagnostic equivalents). We assessed aspects of study quality using: the CONSORT Checklist for evaluation of RCTs, the Cochrane Risk of Bias 2 tool, researcher allegiance and treatment fidelity. The primary outcome was improvement in hypochondriasis symptoms, comparing intervention and control groups at trial endpoint. Moderator variables were assessed using subgroup and meta-regression analyses. Results: Searches identified 13 randomised controlled trials (RCTs) (N = 1405); 12 included CBT (N = 1212) and three included SSRI (N = 193) arms as the experimental intervention. Random effects meta-analysis yielded a moderate-to-large effect size for CBT versus all controls (g = −0.70 [95% CI -0.99 to −0.41], k = 18, I2 = 81.1%). Funnel plot asymmetry indicated possible publication bias and two potentially missing trials, reducing the effect size (g = −0.60 [95% CI -0.88 to −0.32]). Subgroup analysis showed that choice of control significantly moderated effect size, with those in CBT vs. wait-list (g = −1.32 [95% CI -1.75 to −0.90], k = 7, I2 = 0%) being double those of CBT vs. psychological or pharmacological placebo controls (g = −0.58 [95% CI -0.95 to −0.22], k = 7, I2 = 82%). Analysis of studies directly comparing CBT and SSRIs found a numerical, but not statistical advantage for SSRIs (g = 0.21 [95% CI -0.46 to 0.87], k = 2, I2 = 58.34%) and a modest effect size emerged for SSRIs vs. pill placebo (g = −0.29 [95% CI -0.57 to −0.01], k = 3, I2 = 0%). Most studies (11/13) were rated as high on potential researcher allegiance bias in favour of CBT. Meta-regressions revealed that effect sizes were larger in younger participants, and smaller in better quality and more recent RCTs and those with greater CBT fidelity. Conclusion: CBT and SSRIs are effective in the acute treatment of hypochondriasis, with some indication that intervention at a younger age produces better outcomes for CBT. In the case of CBT, effect sizes appear to have been significantly inflated by the use of wait list controls, and researcher allegiance bias. We recommend that a definitive, adequately controlled trial, designed with respect to the methodological issues raised in this meta-analysis, is needed to determine the magnitude effects for CBT and SSRIs with confidence and the long-term effect of treatments, to inform mental health service provision for this overlooked patient group

Monte Carlo study of Si(111) homoepitaxy

An attempt is made to simulate the homoepitaxial growth of a Si(111) surface by the kinetic Monte Carlo method in which the standard Solid-on-Solid model and the planar model of the (7x7) surface reconstruction are used in combination. By taking account of surface reconstructions as well as atomic deposition and migrations, it is shown that the effect of a coorparative stacking transformation is necessary for a layer growth.Comment: 4 pages, 5 figures. For Fig.1 of this article, please see Fig.2 of Phys.Rev. B56, 3583 (1997). To appear in Phys.Rev.B. (June 1998

Non-Zero Sum Games for Reactive Synthesis

In this invited contribution, we summarize new solution concepts useful for the synthesis of reactive systems that we have introduced in several recent publications. These solution concepts are developed in the context of non-zero sum games played on graphs. They are part of the contributions obtained in the inVEST project funded by the European Research Council.Comment: LATA'16 invited pape

Classical Correlation-Length Exponent in Non-Universal Quantum Phase Transition of Diluted Heisenberg Antiferromagnet

Critical behavior of the quantum phase transition of a site-diluted Heisenberg antiferromagnet on a square lattice is investigated by means of the quantum Monte Carlo simulation with the continuous-imaginary-time loop algorithm. Although the staggered spin correlation function decays in a power law with the exponent definitely depending on the spin size $S$, the correlation-length exponent is classical, i.e., $\nu=4/3$. This implies that the length scale characterizing the non-universal quantum phase transition is nothing but the mean size of connected spin clusters.Comment: 4 pages, 3 figure

The eventization of leisure and the strange death of alternative Leeds

The communicative potential of city spaces as leisure spaces is a central assumption of political activism and the creation of alternative, counter-cultural and subcultural scenes. However, such potential for city spaces is limited by the gentrification, privatization and eventization of city centres in the wake of wider societal and cultural struggles over leisure, work and identity formation. In this paper, we present research on alternative scenes in the city of Leeds to argue that the eventization of the city centre has led to a marginalization and of alternative scenes on the fringes of the city. Such marginalization has not caused the death of alternative Leeds or political activism associated with those scenes—but it has changed the leisure spaces (physical, political and social) in which alternative scenes contest the mainstream

Voltage-probe and imaginary potential models for dephasing in a chaotic quantum dot

We compare two widely used models for dephasing in a chaotic quantum dot: The introduction of a fictitious voltage probe into the scattering matrix and the addition of an imaginary potential to the Hamiltonian. We identify the limit in which the two models are equivalent and compute the distribution of the conductance in that limit. Our analysis explains why previous treatments of dephasing gave different results. The distribution remains non-Gaussian for strong dephasing if the coupling of the quantum dot to the electron reservoirs is via ballistic single-mode point contacts, but becomes Gaussian if the coupling is via tunneling contacts.Comment: 9 pages, RevTeX, 6 figures. Mistake in Eq. (35) correcte

New Measurements of the Motion of the Zodiacal Dust

Using the Wisconsin H-Alpha Mapper (WHAM), we have measured at high spectral resolution and high signal-to-noise the profile of the scattered solar Mg I 5184 absorption line in the zodiacal light. The observations were carried out toward 49 directions that sampled the ecliptic equator from solar elongations of 48\dg (evening sky) to 334\dg (morning sky) plus observations near +47\dg and +90\dg ecliptic latitude. The spectra show a clear prograde kinematic signature that is inconsistent with dust confined to the ecliptic plane and in circular orbits influenced only by the sun's gravity. In particular, the broadened widths of the profiles, together with large amplitude variations in the centroid velocity with elongation angle, indicate that a significant population of dust is on eccentric orbits. In addition, the wide, flat-bottomed line profile toward the ecliptic pole indicates a broad distribution of orbital inclinations extending up to about 30\dg - 40\dg with respect to the ecliptic plane. The absence of pronounced asymmetries in the shape of the profiles limits the retrograde population to less than 10% of the prograde population and also places constraints on the scattering phase function of the particles. These results do not show the radial outflow or evening--morning velocity amplitude asymmetry reported in some earlier investigations. The reduction of the spectra included the discovery and removal of extremely faint, unidentified terrestrial emission lines that contaminate and distort the underlying Mg I profile. This atmospheric emission is too weak to have been seen in earlier, lower signal-to-noise observations, but it probably affected the line centroid measurements of previous investigations.Comment: 24 pages, 8 figures, 1 table, to appear in ApJ v612; figures appear low-res only on scree