A comparison of two magnetic ultra-cold neutron trapping concepts using a Halbach-octupole array

This paper describes a new magnetic trap for ultra-cold neutrons (UCNs) made from a 1.2 m long Halbach-octupole array of permanent magnets with an inner bore radius of 47 mm combined with an assembly of superconducting end coils and bias field solenoid. The use of the trap in a vertical, magneto-gravitational and a horizontal setup are compared in terms of the effective volume and ability to control key systematic effects that need to be addressed in high precision neutron lifetime measurements

Viability of competing field theories for the driven lattice gas

It has recently been suggested that the driven lattice gas should be described by a novel field theory in the limit of infinite drive. We review the original and the new field theory, invoking several well-documented key features of the microscopics. Since the new field theory fails to reproduce these characteristics, we argue that it cannot serve as a viable description of the driven lattice gas. Recent results, for the critical exponents associated with this theory, are re-analyzed and shown to be incorrect.Comment: 4 pages, revtex, no figure

Testing Alternative Theories of the Property Price-Trading Volume Correlation

This article examines the correlation between the real housing price and trading volume. Contrary to the predictions of standard rational expectation models, a robust positive correlation between the two variables is identified. While no clear lead-lag relationship is found in the raw data, which is more consistent with the downpayment effect model, the medium-run component of the trading volume tends to lead (and Granger cause) the corresponding component of the property price, which is more consistent with the search theoretic model. An explanation for this difference in behavior is suggested and several future research directions are provided.

Heuristic derivation of continuum kinetic equations from microscopic dynamics

We present an approximate and heuristic scheme for the derivation of continuum kinetic equations from microscopic dynamics for stochastic, interacting systems. The method consists of a mean-field type, decoupled approximation of the master equation followed by the `naive' continuum limit. The Ising model and driven diffusive systems are used as illustrations. The equations derived are in agreement with other approaches, and consequences of the microscopic dependences of coarse-grained parameters compare favorably with exact or high-temperature expansions. The method is valuable when more systematic and rigorous approaches fail, and when microscopic inputs in the continuum theory are desirable.Comment: 7 pages, RevTeX, two-column, 4 PS figures include

Signatures of Fermi surface reconstruction in Raman spectra of underdoped cuprates

We have calculated the Raman B$_{1g}$ and B$_{2g}$ spectra as a function of temperature, as well as doping, for the underdoped cuprates, using a model based on the resonating valence-bond spin-liquid. We discuss changes in intensity and peak position brought about by the presence of a pseudogap and the implied Fermi surface reconstruction, which are elements of this model. Signatures of Fermi surface reconstruction are evident as a sharp rise in the doping dependence of the antinodal to nodal peak ratio which occurs below the quantum critical point. The temperature dependence of the B$_{1g}$ polarization can be used to determine if the superconducting gap is limited to the Fermi pocket, as seen in angle resolved photoemission spectroscopy, or extends beyond. We find that the slope of the linear low energy B$_{2g}$ spectrum maintains its usual d-wave form, but with an effective gap which reflects the gap amplitude projected on the Fermi pocket. Our calculations capture the main qualitative features revealed in the extensive data set available on the HgBa$_2$CuO$_{4+\delta}$ (Hg-1201) cuprate.Comment: 13 pages, 14 figure

Is Perceived Creativity-reward Contingency Good for Creativity? The Role of Challenge and Threat Appraisals

To address the complex effect of perceived reward for creativity on creative performance, we examined the role of cognitive appraisal as an individual difference variable. An individual's appraisal of reward for creativity, including challenge appraisal (perceived potential for recognition, growth, or mastery) and threat appraisal (perceived potential for revealing incompetence and damaging self-respect), is hypothesized to shape the effects of perceived reward for creativity. We further expect creativity-related intrinsic motivation to play a mediating role in the perceived reward-creativity relationship. The results of a three-wave field study showed that when challenge appraisal was high, perceived reward was positively related to creative performance through creativity-related intrinsic motivation, whereas when threat appraisal was high, perceived reward was negatively related to creative performance through creativity-related intrinsic motivation. A similar analysis showed that intrinsic task motivation was not able to channel the moderating effect of perceived reward and individual appraisal on creative performance

Introduction to a landscape analysis of multisectoral approaches for prevention and control of infectious and vector-borne diseases

The Swiss Development Cooperation, Canada's International Development Research Centre, the Swiss Tropical Public Health Institute, and the UNICEF/United Nations Development Programme (UNDP)/World Bank/World Health Organization (WHO) Special Programme for Research and Training in Tropical Diseases (TDR) collaborated on a project to review, understand and promote the use of multisectoral approaches (MSAs) in the prevention and control of vector-borne diseases (VBDs). The objectives of the project were to support a landscape analysis of how MSAs have been used in the prevention and control of VBDs; to develop a theoretical framework for guiding the implementation of interventions; and to test the recommendations in real-life conditions. To realize these objectives, the project supported several activities, including commissioning a series of scientific reviews on MSAs in 5 thematic areas, sharing the key findings of these reviews in workshops and events, and developing a guidance framework for the implementation of MSAs. These activities have produced the theoretical framework that will be tested in real-life conditions through the support of case studies. The collaboration on implementing multisectoral activities against VBDs will continue among TDR, the Swiss Tropical Public Health Institute, and new partners such as the WHO Water Sanitation and Hygiene Group, UNDP, and UN-Habitat, in order to face the challenges identified and propose solutions tailored to specific contexts. The prevention and control of VBDs require strong and adapted MSAs with the full participation of all relevant sectors

Spring-block model for a single-lane highway traffic

A simple one-dimensional spring-block chain with asymmetric interactions is considered to model an idealized single-lane highway traffic. The main elements of the system are blocks (modeling cars), springs with unidirectional interactions (modeling distance keeping interactions between neighbors), static and kinetic friction (modeling inertia of drivers and cars) and spatiotemporal disorder in the values of these friction forces (modeling differences in the driving attitudes). The traveling chain of cars correspond to the dragged spring-block system. Our statistical analysis for the spring-block chain predicts a non-trivial and rich complex behavior. As a function of the disorder level in the system a dynamic phase-transition is observed. For low disorder levels uncorrelated slidings of blocks are revealed while for high disorder levels correlated avalanches dominates.Comment: 6 pages, 7 figure