Stability of water on the Galilean satellites

The selective loss of water from Io under currently prevailing physical conditions was studied to determine whether a large quantity of water can be lost from the satellite over the lifetime of the solar system. Loss processes considered include: thermal escape, photolysis, sputtering, and gas-phase charged particle interactions

High Transmissibility During Early HIV Infection Among Men Who Have Sex With Men-San Francisco, California.

We estimate the relative transmission rate in early versus later infection among men who have sex with men (MSM) in San Francisco, California, by studying the characteristics of a sample of transmitters, recruited through newly diagnosed, recently infected MSM between 1996 and 2009. Of 36 transmitters identified, 9 were determined on the basis of testing history and serologic testing to have been recently infected. The unadjusted odds ratio of transmitting during early infection was 15.2 (95% confidence interval [CI], 6.3–33.4; P < .001); the odds ratio was 8.9 (95% CI, 4.1–19.4) after adjustment for self-reported antiretroviral treatment. This high transmissibility could be due to both high infectiousness and high rates of sex partner change or concurrent partnerships

Recovery of Methane from the Abandoned Golden Eagle Mine Property

The abandoned Golden Eagle underground coal mine in Colorado contains gassy coals from which Stroud Oil Properties, Inc. (Stroud) has been recovering gas since 1996. The mine closed permanently in 1996, and during its operation drained methane from gob and ventilation boreholes. Stroud currently produces about 1.8 million cubic feet of near pipeline quality gas per day from six of these boreholes. Although the project has proven successful, gas recovery has been challenging because of low bottom hole pressure and variable borehole performance. Wellhead compressors are required to boost gas pressure for delivery to the main plant. Connecting additional boreholes to the gathering system often decreases production from existing production boreholes. Increasing gas removal has resulted in air leaks that lower gas quality. Stroud monitors the gas quality and blends any below-spec gas with its above-spec gas to ensure that the resulting product meets pipeline standards. This gas is then compressed for sale into a nearby pipeline. Overburden relaxation and finite difference modeling indicate that overlying coal seams and the coal remaining at the margins of the mined out workings contribute a significant amount of gas to the current production

Effects on transgenic thuringiensis on European corn borer natural enemies and non-target Lepidopteran pests

Field corn, genetically engineered to produce a protein derived from Bacillus thuringiensis, was evaluated for its effects on larvae of black cutworm, stalk borer, armyworm, and corn earworm. No Btcorn effects were observed on larval survival, pupal weight, or days to adult emergence for black cutworm or stalk borer. Armyworms reared on Bt leaf extract were lighter-weight, delayed in development, and showed diminished survival rates. Corn earworm showed reduced survival and delays in development. In field tests of Bt and non-Bt corn, there were no differences between the two varieties in damage from black cutworm. Stalk borer caused less leaf damage to Bt corn. Armyworm and corn earworm did less harm to Bt corn leaves than to non-Bt corn leaves, but corn earworm survived to cause some damage to Bt corn ears

Level-3 Calorimetric Resolution available for the Level-1 and Level-2 CDF Triggers

As the Tevatron luminosity increases sophisticated selections are required to be efficient in selecting rare events among a very huge background. To cope with this problem, CDF has pushed the offline calorimeter algorithm reconstruction resolution up to Level 2 and, when possible, even up to Level 1, increasing efficiency and, at the same time, keeping under control the rates. The CDF Run II Level 2 calorimeter trigger is implemented in hardware and is based on a simple algorithm that was used in Run I. This system has worked well for Run II at low luminosity. As the Tevatron instantaneous luminosity increases, the limitation due to this simple algorithm starts to become clear: some of the most important jet and MET (Missing ET) related triggers have large growth terms in cross section at higher luminosity. In this paper, we present an upgrade of the Level 2 Calorimeter system which makes the calorimeter trigger tower information available directly to a CPU allowing more sophisticated algorithms to be implemented in software. Both Level 2 jets and MET can be made nearly equivalent to offline quality, thus significantly improving the performance and flexibility of the jet and MET related triggers. However in order to fully take advantage of the new L2 triggering capabilities having at Level 1 the same L2 MET resolution is necessary. The new Level-1 MET resolution is calculated by dedicated hardware. This paper describes the design, the hardware and software implementation and the performance of the upgraded calorimeter trigger system both at Level 2 and Level 1.Comment: 5 pages, 5 figures,34th International Conference on High Energy Physics, Philadelphia, 200

Adjusting for sampling variability in sparse data: geostatistical approaches to disease mapping

Abstract Background Disease maps of crude rates from routinely collected health data indexed at a small geographical resolution pose specific statistical problems due to the sparse nature of the data. Spatial smoothers allow areas to borrow strength from neighboring regions to produce a more stable estimate of the areal value. Geostatistical smoothers are able to quantify the uncertainty in smoothed rate estimates without a high computational burden. In this paper, we introduce a uniform model extension of Bayesian Maximum Entropy (UMBME) and compare its performance to that of Poisson kriging in measures of smoothing strength and estimation accuracy as applied to simulated data and the real data example of HIV infection in North Carolina. The aim is to produce more reliable maps of disease rates in small areas to improve identification of spatial trends at the local level. Results In all data environments, Poisson kriging exhibited greater smoothing strength than UMBME. With the simulated data where the true latent rate of infection was known, Poisson kriging resulted in greater estimation accuracy with data that displayed low spatial autocorrelation, while UMBME provided more accurate estimators with data that displayed higher spatial autocorrelation. With the HIV data, UMBME performed slightly better than Poisson kriging in cross-validatory predictive checks, with both models performing better than the observed data model with no smoothing. Conclusions Smoothing methods have different advantages depending upon both internal model assumptions that affect smoothing strength and external data environments, such as spatial correlation of the observed data. Further model comparisons in different data environments are required to provide public health practitioners with guidelines needed in choosing the most appropriate smoothing method for their particular health dataset

Risky Business: The Issue of Timing, Entry and Performance in the Asia-Pacific LNG Market

Canada’s federal government has championed the prospect of exporting liquefied natural gas (LNG) to overseas markets. The government of British Columbia is aggressively planning to turn itself into a global LNG-export hub, and the prospect for Canadian LNG exports is positive. However, there are market and political uncertainties that must be overcome in a relatively short period of time if Canada is to become a natural gas exporter to a country other than the United States. This report assesses the feasibility of Canadian exports and examines the policy challenges involved in making the opportunity a reality. Demand for natural gas in the Asia-Pacific region is forecast to grow over 60 per cent by 2025. LNG trade is expected to make up nearly two-thirds of global natural gas trade by 2035. Supply in the Asia-Pacific region is limited, requiring significant LNG imports with corresponding infrastructure investment. This results in substantial price differentials between North America and the Asia-Pacific countries, creating a potentially lucrative opportunity for Canada. The lower North American prices are a reflection of the fact that there is a surplus of gas on this continent. Canada’s shipments to its sole export market, the United States, are shrinking in the face of vast increases in American production of shale and tight gas. Canada has a surplus of natural gas and there is growing demand in the Asia-Pacific region. Proponents argue that all Canada needs to do is build and supply facilities to liquefy gas and ship it across the Pacific; the reality is not so simple. Timing is one of the key challenges Canada faces. Producers around the world — including in the newly gas-rich U.S. — are racing to lock up market-share in the Asia-Pacific region, in many cases much more aggressively than Canada. While this market is robust and growing, the nature of the contracts for delivery will favour actors that are earliest in the queue; margins for those arriving late will be slimmer and less certain over time. As supply grows, so too does the likelihood of falling gas prices in the Asia-Pacific region, making later projects less lucrative. LNG projects are feasible only on the basis of long-term contracts; once a piece of market share is acquired, it could be decades before it becomes available again. Currently, there are more proposed LNG-export projects around the world than will be required to meet projected demand for the foreseeable future. Delays beyond 2024 risk complete competitive loss of market entry for Canadian companies. B.C. is behind schedule on the government’s goal of having a single terminal operational by 2015. Of equal concern is the lack of policy and regulatory co-ordination, with disagreements between governments over standards, process and compensation for those stakeholders involved in the potential LNG industry. Issues as basic as taxing and royalty charges for gas shipments between provinces and locating facilities and marine-safety standards remain unsettled in Canada. The B.C. government has announced plans to levy special taxes on LNG, a policy that could render many current proposals uncompetitive. The LNG market is much more complicated than current discussions suggest; this report delves into every aspect relevant for Canada as a potential exporter. The prospect for Canada expanding into the Asia-Pacific market is entirely viable. Canada has almost everything going for it: political stability, free-market principles, immense resources, extensive infrastructure and industry experience. Everything, that is, except a co-ordinated regulatory and policy regime. Without that, Canada could be shut out, stuck relying on a single U.S. gas-export market that, increasingly, does not need us

Carey Young’s 'Palais de Justice'

The symposium for this issue comprises six responses to the video artwork Palais de Justice (2017) by artist Carey Young. The video presents a study of the life of Brussels’ vast, late-nineteenth-century court building. In Palais de Justice, Young presents ‘a legal system seemingly centered on, and perhaps controlled by women’. The respondents are Jeanne Gaakeer, Ruth Herz, Joan Kee, Linda Mulcahy, Jeremy Pilcher and Gary Watt. Jeanne Gaakeer and Ruth Herz have the distinction of being, not only internationally respected scholars, but also experienced judges. Jeanne Gaakeer is a judge practicing in the Netherlands and Ruth Herz was formerly a judge in Germany. The six responses are followed by the artist’s own reflections on her artwork and her response to the commentators’ responses. Joan Kee writes that ‘Young highlights access as a key entry point for thinking about the law. Who can avail themselves of the law? Who may enter (or exit) the courts? Who is excluded and by whose authority? The surreptitious looking and peering that define the experience of watching the film suggests how these questions deny ready answers’