22,868 research outputs found

    Differential forms, Fukaya A∞A_\infty algebras, and Gromov-Witten axioms

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    Consider the differential forms Aβˆ—(L)A^*(L) on a Lagrangian submanifold LβŠ‚XL \subset X. Following ideas of Fukaya-Oh-Ohta-Ono, we construct a family of cyclic unital curved A∞A_\infty structures on Aβˆ—(L),A^*(L), parameterized by the cohomology of XX relative to L.L. The family of A∞A_\infty structures satisfies properties analogous to the axioms of Gromov-Witten theory. Our construction is canonical up to A∞A_\infty pseudoisotopy. We work in the situation that moduli spaces are regular and boundary evaluation maps are submersions, and thus we do not use the theory of the virtual fundamental class.Comment: 51 pages, 6 figures; improved exposition, added illustrations, corrected minor errors, added reference

    Evaluation of the organisation and delivery of patient-centred acute nursing care

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    In 2002, a team of researchers from the School of Nursing, University of Salford were commissioned by Bolton Hospitals NHS Trust to evaluate the delivery and organisation of patient-centred nursing care across the acute nursing wards within the Royal Bolton Hospital. The key driver for the commissioning of this study arose from two serious untoward incidents that occurred in the year 2000. Following investigation of both these events the Director of Nursing in post at that time believed that poor organisation and delivery of care may have been a contributory factor. Senior nurses in the Trust had also expressed their concern that care may not be organised in a way that made best use of the skills available

    The essential signature of a massive starburst in a distant galaxy

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    Observations of carbon monoxide (CO) emission in high redshift (z>2) galaxies indicate the presence of large amounts of molecular gas. Many of these galaxies contain an active galactic nucleus (AGN) powered by accretion of gas onto a supermassive black hole, and a key question is whether their extremely high infrared luminosities result from the AGN, or from bursts of massive star formation (associated with the molecular gas), or both. In the Milky Way, high-mass stars form in the dense cores of interstellar molecular clouds; gas densities are n(H2)>105 cm-3 in the cores. Recent surveys show that virtually all galactic sites of high-mass star formation have similarly high densities. The bulk of the cloud material traced by CO observations is at a much lower density. In galaxies in the local Universe, the HCN(J=1-0) line is an effective tracer of the high-density molecular gas. Here we report observations of HCN emission in the early Universe from the infrared luminous 'Cloverleaf' quasar (at a redshift z=2.5579). The HCN line luminosity indicates the presence of 10 billion solar masses of very dense gas, an essential feature of an immense starburst that contributes, together with the AGN it harbors, to its high infrared luminosity.Comment: PDF pape
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