2,605 research outputs found

    A probabilistic approach to quantum Bayesian games of incomplete information

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    A Bayesian game is a game of incomplete information in which the rules of the game are not fully known to all players. We consider the Bayesian game of Battle of Sexes that has several Bayesian Nash equilibria and investigate its outcome when the underlying probability set is obtained from generalized Einstein-Podolsky-Rosen experiments. We find that this probability set, which may become non-factorizable, results in a unique Bayesian Nash equilibrium of the game.Comment: 18 pages, 2 figures, accepted for publication in Quantum Information Processin

    Role of correlated two-pion exchange in K+NK^+ N scattering

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    A dynamical model for S-- and P--wave correlated 2π2 \pi (and KKˉK \bar K) exchange between a kaon and a nucleon is presented, starting from corresponding NNˉKKˉN \bar N \rightarrow K \bar K amplitudes in the pseudophysical region, which have been constructed from nucleon, Δ\Delta--isobar and hyperon (Λ\Lambda, Σ\Sigma) exchange Born terms and a realistic meson exchange model of the ππKKˉ\pi \pi \rightarrow K \bar K and KKˉKKˉK \bar K \rightarrow K \bar K amplitude. The contribution in the s--channel is then obtained by performing a dispersion relation over the unitarity cut. In the ρ\rho--channel, considerable ambiguities exist, depending on how the dispersion integral is performed. Our model, supplemented by short range interaction terms, is able to describe empirical K+NK^+ N data below pion production threshold in a satisfactory way.Comment: 24 pages, REVTEX, figures available from the author

    Sr-Nd-Pb-Hf isotope results from ODP Leg 187: Evidence for mantle dynamics of the Australian-Antarctic Discordance and origin of the Indian MORB source

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    New high precision PIMMS Hf and Pb isotope data for 14–28 Ma basalts recovered during ODP Leg 187 are compared with zero-age dredge samples from the Australian-Antarctic Discordance (AAD). These new data show that combined Nd-Hf isotope systematics can be used as an effective discriminant between Indian and Pacific MORB source mantle domains. In particular, Indian mantle is displaced to lower εNd and higher εHf ratios compared to Pacific mantle. As with Pb isotope plots, there is almost no overlap between the two mantle types in Nd-Hf isotope space. On the basis of our new Nd-Hf isotope data, we demonstrate that Pacific MORB-source mantle was present near the eastern margin of the AAD from as early as 28 Ma, its boundary with Indian MORB-source mantle coinciding with the eastern edge of a basin-wide arcuate depth anomaly that is centered on the AAD. This observation rules out models requiring rapid migration of Pacific MORB mantle into the Indian Ocean basin since separation of Australia from Antarctica. Although temporal variations in isotopic composition can be discerned relative to the fracture zone boundary of the modern AAD at 127°E, the distribution of different compositional groups appears to have remained much the same relative to the position of the residual depth anomaly for the past 30 m.y. Thus significant lateral flow of mantle along the ridge axis toward the interface appears unlikely. Instead, the dynamics that maintain both the residual depth anomaly and the isotopic boundary between Indian and Pacific mantle are due to eastward migration of the Australian and Antarctic plates over a stagnated, but slowly upwelling, slab oriented roughly orthogonal to the ridge axis. Temporal and spatial variations in the compositions of Indian MORB basalts within the AAD can be explained by progressive displacement of shallower Indian MORB-source mantle by deeper mantle having a higher εHf composition ascending ahead of the upwelling slab. Models for the origin of the distinctive composition of the Indian MORB-source based on recycling of a heterogeneous enriched component that consist of ancient altered ocean crust plus<10% pelagic sediment are inconsistent with Nd-Hf isotope systematics. Instead, the data can be explained by a model in which Indian mantle includes a significant proportion of material that was processed in the mantle wedge above a subduction zone and was subsequently mixed back into unprocessed upper mantle

    Kraft's number and ideal word packing

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    N. M. Dragomir, S. S. Dragomir, C. E. M. Pearce and J. Sund

    Covalently Crosslinked Nanogels: An NMR Study of the Effect of Monomer Reactivity on Composition and Structure

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    Covalently crosslinked nanogels are widely explored as drug delivery systems and sensors. Radical polymerization provides a simple, inexpensive, and broadly applicable approach for their preparation, although the random nature of the reaction requires careful study of the final chemical composition. We demonstrate how the different reactivities of the monomers influence the total degree of incorporation into the polymer matrix and the role played by the experimental parameters in maximizing polymerization efficiency. Nanogels based on N-isopropylacrylamide, N-n-propylacrylamide, and acrylamide crosslinked with N,N’-methylenebisacrylamide were included in this study, in combination with functional monomers N-acryloyl-l-proline, 2-acrylamido-2-methyl-1-propanesulfonic acid, and 4-vinyl-1H-imidazole. Total monomer concentration and initiator quantities are determining parameters for maximizing monomer conversions and chemical yields. The results show that the introduction of functional monomers, changes in the chemical structure of the polymerizable unit, and the addition of templating molecules can all have an effect on the polymerization kinetics. This can significantly impact the final composition of the matrices and their chemical structure, which in turn influence the morphology and properties of the nanogels

    Leg strength in peripheral arterial disease: associations with disease severity and lower-extremity performance

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    AbstractObjectiveThe purpose of this study was to determine relationships between lower-extremity arterial obstruction, leg strength, and lower-extremity functioning.DesignThe study design was cross-sectional. A total of 514 outpatients (269 with ankle-brachial index [ABI] <0.90), aged 55 and older, were identified from three Chicago-area hospitals. Individuals with history of lower-extremity revascularization were excluded.Main outcome measuresStrength in each leg, 6-minute walk, 4-meter walking velocity, accelerometer-measured physical activity, and a summary performance score were measured. The summary performance score is a composite measure of lower-extremity functioning, ranging from 0 to 12 (12 = best). The leg with the lower ABI was defined as the “index” leg, and the leg with higher ABI was defined as the “contralateral” leg.ResultsIndex leg ABI levels were associated linearly and significantly with strength for hip extension (P < .001), hip flexion (P < .001), knee extension (P = .066), and knee flexion (P = .003), adjusting for known and potential confounders. In adjusted analyses, the index ABI was also associated linearly and significantly with strength in the contralateral leg. Adjusting for confounders, including ABI, knee extension strength, was associated independently with functional measures.ConclusionAmong patients without prior leg revascularization, strength in each leg is highly correlated with the lower-leg ABI. Leg strength is associated independently with functional performance. Further study is needed to determine whether lower-extremity resistance training improves functioning in patients with peripheral arterial disease

    Following the funding trail: Financing, nurses and teamwork in Australian general practice

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    Contains fulltext : 97927.pdf (publisher's version ) (Open Access)BACKGROUND: Across the globe the emphasis on roles and responsibilities of primary care teams is under scrutiny. This paper begins with a review of general practice financing in Australia, and how nurses are currently funded. We then examine the influence on funding structures on the role of the nurse. We set out three dilemmas for policy-makers in this area: lack of an evidence base for incentives, possible untoward impacts on interdisciplinary functioning, and the substitution/enhancement debate. METHODS: This three year, multimethod study undertook rapid appraisal of 25 general practices and year-long studies in seven practices where a change was introduced to the role of the nurse. Data collected included interviews with nurses (n = 36), doctors (n = 24), and managers (n = 22), structured observation of the practice nurse (51 hours of observation), and detailed case studies of the change process in the seven year-long studies. RESULTS: Despite specific fee-for-service funding being available, only 6% of nurse activities generated such a fee. Yet the influence of the funding was to focus nurse activity on areas that they perceived were peripheral to their roles within the practice. CONCLUSIONS: Interprofessional relationships and organisational climate in general practices are highly influential in terms of nursing role and the ability of practices to respond to and utilise funding mechanisms. These factors need to be considered, and the development of optimal teamwork supported in the design and implementation of further initiatives that financially support nursing in general practice
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