Evolving relativistic fluid spacetimes using pseudospectral methods and finite differencing

We present a new code for solving the coupled Einstein-hydrodynamics equations to evolve relativistic, self-gravitating fluids. The Einstein field equations are solved on one grid using pseudospectral methods, while the fluids are evolved on another grid by finite differencing. We discuss implementation details, such as the communication between the grids and the treatment of stellar surfaces, and present code tests.Comment: To appear in the Proceedings of the Eleventh Marcel Grossmann Meetin

Building Stones of Canada's Federal Parliament Buildings

The building stones used in the Ottawa Parliament Buildings were mined from numerous quarries in Canada, United States, and several European nations.They were cut, placed and carved according to exacting procedures using the most up-to-date technology of the time. Construction of the rebuilt Centre Block, the focus of this article, was a protracted affair, interrupted by the demands of the1914-1918 Great War. Exterior stone of the Parliament Buildings has endured the ravages of weather, fire, seismic shaking and pollution. Recently, great effort and expense have been devoted to the restoration of the masonry elements of all of the buildings to ensure the continued viability of this National Historic Site.The role of the geologist, critical in the initial evaluation and selection of the building stone, was largely ignored until recently. Building restoration of late has also restored the role of the geologist, with the requirement to understand the complex reactions of the building stone to the environment and its neighbouring masonry elements, and in the quest to find suitable replacement stone. Résumé Les pierres de construction utilisées pour les édifices du Parlement à Ottawa proviennent de nombreuses carrières autant au Canada, aux États-Unis que de plusieurs pays européens. Elles ont été taillées, posées et sculptées suivant des procédés précis, en conformité avec les règles de l'art de l'époque. La reconstruction de l'édifice du centre qui est le sujet du présent article, a été une affaire qui s'est étirée étant donné les priorités lors de la Grande Guerre de 1914-1918. Ces pierres de revêtement des édifices du Parlement ont subi les avanies du climat, du feu, de tremblements de terre et de la pollution, et récemment, des efforts et des fonds considérables ont été consentis pour la restauration des éléments de maçonnerie de tous les édifices afin d'assurer la pérennité de ce site historique national. Le rôle déterminant du géologue, lors de l'évaluation initiale et du choix des pierres, a été largement ignoré jusqu'à maintenant, mais la restauration des édifices a permis de remettre en valeur le rôle du géologue, parce qu'il fallait d'abord comprendre les réactions complexes des pierres de construction avec l'environnement et les autres éléments de maçonnerie avoisinants, afin de pouvoir trouver des pierres de remplacement convenables

Experimental validation of phase space conduits of transition between potential wells

A phase space boundary between transition and non-transition, similar to those observed in chemical reaction dynamics, is shown experimentally in a macroscopic system. We present a validation of the phase space flux across rank one saddles connecting adjacent potential wells and confirm the underlying phase space conduits that mediate the transition. Experimental regions of transition are found to agree with the theory to within 1\%, suggesting the robustness of phase space conduits of transition in a broad array of two or more degree of freedom experimental systems, despite the presence of small dissipation.Comment: 7 pages, 6 figure

Gamma ray pulsar analysis from photon probability maps

A new method is presented of analyzing skymap-type gamma ray data. Each photon event is replaced by a probability distribution on the sky corresponding to the observing instrument's point spread function. The skymap produced by this process may be used for source detection or identification. Most important, the use of these photon weights for pulsar analysis promises significant improvement over traditional techniques

Gamma ray pulsar analysis from photon pobability maps

We present a new method of analyzing skymap-type gamma ray data. Each photon event is replaced by a probability distribution on the sky corresponding to the observing instrument's point spread function. The skymap produced by this process may be used for source detection or identification. Most important, the use of these photon weights for pulsar analysis promises significant improvement over traditional techniques

Warming winters and New Hampshire’s lost ski areas: An integrated case study

New Hampshire’s mountains and winter climate support a ski industry that contributes substantially to the state economy. Through more than 70 years of history, this industry has adapted and changed with its host society. The climate itself has changed during this period too, in ways that influenced the ski industry’s development. During the 20th century, New Hampshire’s mean winter temperature warmed about 2.1° C (3.8° F). Much of that change occurred since 1970. The mult‐decadal variations in New Hampshire winters follow global temperature trends. Snowfall exhibits a downward trend, strongest in southern New Hampshire, and also correlates with the North Atlantic Oscillation. Many small ski areas opened during the early years while winters were cold and snowy. As winters warmed, areas in southern or lowelevation locations faced a critical disadvantage. Under pressure from both climate and competition, the number of small ski areas leveled off and then fell steeply after 1970. The number of larger, chairliftoperating ski areas began falling too after 1980. Aprolonged warming period increased the importance of geographic advantages, and also of capital investment in snowmaking, grooming and economic diversification. The consolidation trend continues today. Most of the surviving ski areas are located in the northern mountains. Elsewhere around the state, one can find the remains of “lost” ski areas in places that now rarely have snow suitable for downhill skiing. This case study demonstrates a general approach for conducting integrated empirical research on the human dimensions of climate change

Restoring Health to Health Reform: Integrating Medicine and Public Health to Advance the Population\u27s Wellbeing

The Patient Protection and Affordable Care Act is a major achievement in improving access to health care services. However, evidence indicates that the nation could achieve greater improvements in health outcomes, at a lower cost, by shifting its focus to public health. By focusing nearly exclusively on health care, policy makers have chronically starved public health of adequate and stable funding and political support. The lack of support for public health is exacerbated by the fact that health care and public health are generally conceptualized, organized, and funded as two separate systems. In order to maximize gains in health status and to spend scarce health resources most effectively, health care and public health should be treated as two interactive parts of a single, unified health system. The core purpose of health reform ought to be the improvement of the population’s health. We propose five criteria that would significantly advance this goal: prevention and wellness, human resources, a strong and sustainable health infrastructure, robust performance measurement, and reduction of health disparities. Although the Patient Protection and Affordable Care Act includes provisions addressing these criteria, population health is not a central focus of the reform. In order to guide health reform implementation and to inform future health reform efforts, we offer three major policy reforms: changing the environment to incentivize healthy behavioral choices, strengthening the public health infrastructure at the state and local levels, and developing a health-in-all policies strategy that would engage multiple agencies in improving health incomes. Adopting these reforms would facilitate integration and dramatically improve the population’s health, particularly when compared to the health gains likely to be realized from a continued focus on access to health care services