Hide and Seek in Arizona

Laboratory subjects repeatedly played one of two variations of a simple two-person zero-sum game of ``hide and seek.'' Three puzzling departures from the prescriptions of equilibrium theory are found in the data: an asymmetry related to the player's role in the game; an asymmetry across the game variations; and positive serial correlation in subjects' play. Possible explanations for these departures are considered.Minimax, mixed strategy, experiment

Arsenic Consumption and Health Risk Perceptions in a Rural Western U.S. Area

Churchill County, Nevada had approximately 23,000 residents, with an estimated 13,500 who relied on private wells for water supply in 2002. This study examined exposure to arsenic in water supplies among residents with private domestic wells and factors related to householder choice to consume tap water. It compared opinions and concerns about water quality with consumption habits and observed concentrations from tap water samples. The results from 351 households indicated that a majority (75%) of respondents consumed tap water and that a minority (38%) applied treatment. Approximately 66% of those who consumed tap water were exposed to concentrations of arsenic that exceeded 10 ppb. Water consumption was related to application of treatment. Among 98 respondents who were not at all concerned about the health effects of aqueous arsenic, 59 (60%) reported consuming tap water with concentrations of arsenic exceeding 10 ppb. Conversely, among 86 respondents who were highly concerned about arsenic, 33 (37%) consumed tap water with concentrations of arsenic exceeding 10 ppb. Results from a national sampling effort showed that 620/5304 (11.7%) of private wells sampled had arsenic concentrations above 10 ppb. The paradox of awareness of arsenic in water supplies coupled with consumption of aqueous arsenic in concentrations of >10 ppb may be common in other parts of the nation. Enhanced educational efforts, especially related to tap water sampling and explanations of efficacy of available treatment, may be a useful means of reducing exposure through private water supplies.Health Economics and Policy, Resource /Energy Economics and Policy,

Hochster's theta invariant and the Hodge-Riemann bilinear relations

Let R be an isolated hypersurface singularity, and let M and N be finitely generated R-modules. As R is a hypersurface, the torsion modules of M against N are eventually periodic of period two (i.e., Tor_i^R(M,N) is isomorphic to Tor_{i+2}^R(M,N) for i sufficiently large). Since R has only an isolated singularity, these torsion modules are of finite length for i sufficiently large. The theta invariant of the pair (M,N) is defined by Hochster to be length(Tor_{2i}^R(M,N)) - length(Tor_{2i+1}^R(M,N)) for i sufficiently large. H. Dao has conjectured that the theta invariant is zero for all pairs (M,N) when R has even dimension and contains a field. This paper proves this conjecture under the additional assumption that R is graded with its irrelevant maximal ideal giving the isolated singularity. We also give a careful analysis of the theta pairing when the dimension of R is odd, and relate it to a classical pairing on the smooth variety Proj(R).Comment: 20 page

Risk Perceptions of Arsenic in Tap Water and Consumption of Bottled Water

The demand for bottled water has increased rapidly over the past decade, but bottled water is extremely costly compared to tap water. The convenience of bottled water surely matters to consumers, but are others factors at work? This manuscript examines whether purchases of bottled water are associated with the perceived risk of tap water. All of the past studies on bottled water consumption have used simple scale measures of perceived risk that do not correspond to risk measures used by risk analysts. We elicit a probability-based measure of risk and find that as perceived risks rise, expenditures for bottled water rise.Environmental Economics and Policy, Risk and Uncertainty, Q25, Q53, I12,

TimeNotes: A Study on Effective Chart Visualization and Interaction Techniques for Time-Series Data

Collecting sensor data results in large temporal data sets which need to be visualized, analysed, and presented. One dimensional time-series charts are used, but these present problems when screen resolution is small in comparison to the data. This can result in severe over-plotting, giving rise for the requirement to provide effective rendering and methods to allow interaction with the detailed data. Common solutions can be categorized as multi-scale representations, frequency based, and lens based interaction techniques. In this paper, we comparatively evaluate existing methods, such as Stack Zoom [15] and ChronoLenses [39], giving a graphical overview of each and classifying their ability to explore and interact with data. We propose new visualizations and other extensions to the existing approaches. We undertake and report an empirical study and a field study using these techniques

Performance Limits of Labriform Propulsion and Correlates with Fin Shape and Motion

Labriform locomotion, which is powered by oscillating the paired pectoral fins, varies along a continuum from rowing the fins back and forth to flapping the fins up and down. It has generally been assumed (i) that flapping is more mechanically efficient than rowing, a hypothesis confirmed by a recent simulation experiment, and (ii) that flapping should be associated with wing-shaped fins while rowing should be associated with paddle-shaped fins, To determine whether these hypotheses and the results of the simulation experiment are consistent with natural variation, we compared the steady swimming performance (critical swimming speed) of four species of labrid fish (Cirrhilabrus rubripinnis, Pseudocheilinus octolaenia, Gomphosus varius and Halichoeres bivittatus) selected to form two pairs of closely related species that vary in fin shape and in the direction of fin motion. The results were consistent with expectations. Within each pair, the species with the best swimming performance also had (i) a fin shape characterized by a higher aspect ratio, a longer leading edge relative to the trailing edge fin rays and the center of fin area located closer to: the fin base, and (ii) a steeper (more dorsoventral) stroke, plane

TPL-2 restricts Ccl24-dependent immunity to Heligmosomoides polygyrus

Funding: This work was supported by the Francis Crick Institute which receives its core funding from Cancer Research UK (FC001220), the UK Medical Research Council (FC001220), and the Wellcome Trust (FC001200). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgments We are indebted to The Francis Crick Institute Flow Cytometry facility, and in particular Bhavik Patel, Graham Preece, Wayne Turnbull and Phil Hobson. We would also like to thank The Francis Crick Institute Procedural Service Section for production of GA lines and Biological Services, especially Trisha Norton, Keith Williams and Adebambo Adekoya for animal husbandry and technical support; to Riccardo Guidi for constructive discussions and technical assistance. We would like to thank Gitta Stockinger and AhR Immunity Laboratory for providing technical support and reagents throughout this study. We also thank Richard Rance and the Wellcome Trust Sanger Institute’s 454 pyrosequencing team for generating 16S rRNA gene data.Peer reviewedPublisher PD

The Electronic and Superconducting Properties of Oxygen-Ordered MgB2 compounds of the form Mg2B3Ox

Possible candidates for the Mg2B3Ox nanostructures observed in bulk of polycrystalline MgB2 (Ref.1) have been studied using a combination of Z-contrast imaging, electron energy loss spectroscopy (EELS) and first-principles calculations. The electronic structures, phonon modes, and electron phonon coupling parameters are calculated for two oxygen-ordered MgB2 compounds of composition Mg2B3O and Mg2B3O2, and compared with those of MgB2. We find that the density of states for both Mg2B3Ox structures show very good agreement with EELS, indicating that they are excellent candidates to explain the observed coherent oxygen precipitates. Incorporation of oxygen reduces the transition temperature and gives calculated TC values of 18.3 K and 1.6 K for Mg2B3O and Mg2B3O2, respectively.Comment: Submitted to PR