3,995 research outputs found

    Supergravity, Supermembrane and M(atrix) model on PP-Waves

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    In the first part of this paper, we study the back-reaction of large-N light cone momentum on the maximally supersymmetric anti-pp-wave background. This gives the type IIA geometry of large-N D0-branes on curved space with fluxes. By taking an appropriate decoupling limit, we conjecture a new duality between string theory on that background and dual field theory on D0-branes which we derive by calculating linear coupling terms. Agreement of decoupling quantities, SO(3) \times SO(6) isometry and Higgs branch on both theories are shown. Also we find whenever dual field theory is weakly coupled, the curvature of the geometry is large. In the second part of this paper, we derive the supermembrane action on a general pp-wave background only through the properties of null Killing vector and through this, derive the Matrix model.Comment: 19 pages, LaTeX. v2: corrected interpretation of supergravity solutio

    On BPS bounds in D=4 N=2 gauged supergravity II: general matter couplings and black hole masses

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    We continue the analysis of BPS bounds started in arXiv:1110.2688, extending it to the full class of N=2 gauged supergravity theories with arbitrary vector and hypermultiplets. We derive the general form of the asymptotic charges for asymptotically flat (M_4), anti-de Sitter (AdS_4), and magnetic anti-de Sitter (mAdS_4) spacetimes. Some particular examples from black hole physics are given to explicitly demonstrate how AdS and mAdS masses differ when solutions with non-trivial scalar profiles are considered.Comment: 21 pages; v2 added reference, published version; v3 minor correction

    Soluble or insoluble fibre in irritable bowel syndrome in primary care? Randomised placebo controlled trial

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    Objective To determine the effectiveness of increasing the dietary content of soluble fibre (psyllium) or insoluble fibre (bran) in patients with irritable bowel syndrome

    The Hypermultiplet with Heisenberg Isometry in N=2 Global and Local Supersymmetry

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    The string coupling of N=2 supersymmetric compactifications of type II string theory on a Calabi-Yau manifold belongs to the so-called universal dilaton hypermultiplet, that has four real scalars living on a quaternion-Kaehler manifold. Requiring Heisenberg symmetry, which is a maximal subgroup of perturbative isometries, reduces the possible manifolds to a one-parameter family that describes the tree-level effective action deformed by the only possible perturbative correction arising at one-loop level. A similar argument can be made at the level of global supersymmetry where the scalar manifold is hyper-Kaehler. In this work, the connection between global and local supersymmetry is explicitly constructed, providing a non-trivial gravity decoupled limit of type II strings already in perturbation theory.Comment: 24 page

    A new purple sulfur bacterium from saline littoral sediments, Thiorhodotvibrio winogradskyi gen. nov. and sp. nov.

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    Two strains of a new purple sulfur bacterium were isolated in pure culture from the littoral sediment of a saline lake (Mahoney Lake, Canada) and a marine microbial mat from the North Sea island of Mellum, respectively. Single cells were vibrioid-to spirilloid-shaped and motile by means of single polar flagella. Intracellular photosynthetic membranes were of the vesicular type. As photosynthetic pigments, bacteriochlorophyll a and the carotenoids lycopene, rhodopin, anhydrorhodovibrin, rhodovibrin and spirilloxanthin were present. Hydrogen sulfide and elemental sulfur were used under anoxic conditions for phototrophic growth. In addition one strain (06511) used thiosulfate. Carbon dioxide, acetate and pyruvate were utilized by both strains as carbon sources. Depending on the strain propionate, succinate, fumarate, malate, tartrate, malonate, glycerol or peptone may additionally serve as carbon sources in the light. Optimum growth rates were obtained at pH 7.2, 33 °C, 50 mol m-2 s-1 intensity of daylight fluorescent tubes and a salinity of 2.2–3.2% NaCl. During growth on sulfide, up to ten small sulfur globules were formed inside the cells. The strains grew microaerophilic in the dark and exhibited high specific respiration rates. No vitamins were required for growth. The DNA base composition was 61.0–62.4 mol% G+C. The newly isolated bacterium belongs to the family chromatiaceae and is described as a member of a new genus and species, Thiorhodovibrio winogradskyi gen. nov. and sp. nov. with the type strain SSP1, DSM No. 6702

    Op weg naar cultuursensitieve zorg voor oudere migranten! Opzet en werkwijze van het Stem van de Oudere Migrant project

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    Achtergrond De zorg- en welzijnsvoorzieningen zijn niet goed toegankelijk voor oudere migranten en aan hun behoeften en wensen wordt door het huidige aanbod niet optimaal voldaan. Overgang naar een meer cultuursensitieve organisatie van zorg en welzijn is daarom nodig. Het Stem van de Oudere Migrant-project (Netwerk Utrecht Zorg voor Ouderen (NUZO) van het UMC Utrecht en partners) ontwikkelde met dit doel een programma met als interventie de inzet van zogenaamde sleutelfiguren uit de eigen gemeenschap van de doelgroep ouderen. De sleutelfiguur dient als brug tussen de ouderen en de professionals. Opzet Door middel van een quasi-experimenteel design wordt de inzet van de sleutelfiguren geëvalueerd in drie stedelijke gebieden in Nederland (Utrecht, Harderwijk en Tiel en een controlegroep uit Amsterdam en Maarssen) onder drie migrantengroepen. De primaire uitkomstmaat is gebruik van zorg- en welzijnsvoorzieningen. Secundaire uitkomstmaten zijn kwaliteit van leven en het aantal functionele beperkingen. Het proces wordt kwalitatief geëvalueerd door focusgroepen en registratie van de werkzaamheden van de sleutelfiguur. In dit artikel worden de opzet en methodologische keuzes toegelicht. Discussie Deze studie kan bijdragen aan de verbetering van het cultuursensitief zijn van de zorg en welzijn aan oudere migranten. De doelgroep wordt actief betrokken bij dit project. Het identificeren van de juiste sleutelfiguren is voor het slagen van het project van groot belang. Doelstelling is bij gebleken effectiviteit de sleutelfiguur te integreren als een bestaand onderdeel van de lokale zorg- en welzijnsvoorzieningen

    Colorectal anastomotic leak:Transcriptomic profile analysis

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    BACKGROUND: Anastomotic leakage in patients undergoing colorectal surgery is associated with morbidity and mortality. Although multiple risk factors have been identified, the underlying mechanisms are mainly unknown. The aim of this study was to perform a transcriptome analysis of genes underlying the development of anastomotic leakage. METHODS: A set of human samples from the anastomotic site collected during stapled colorectal anastomosis were used in the study. Transcriptomic profiles were generated for patients who developing anastomotic leakage and case-matched controls with normal anastomotic healing to identify genes and biological processes associated with the development of anastomotic leakage. RESULTS: The analysis included 22 patients with and 69 without anastomotic leakage. Differential expression analysis showed that 44 genes had adjusted P < 0.050, consisting of two upregulated and 42 downregulated genes. Co-functionality analysis of the 150 most upregulated and 150 most downregulated genes using the GenetICA framework showed formation of clusters of genes with different enrichment for biological pathways. The enriched pathways for the downregulated genes are involved in immune response, angiogenesis, protein metabolism, and collagen cross-linking. The enriched pathways for upregulated genes are involved in cell division. CONCLUSION: These data indicate that patients who develop anastomotic leakage start the healing process with an error at the level of gene regulation at the time of surgery. Despite normal macroscopic appearance during surgery, the transcriptome data identified several differences in gene expression between patients who developed anastomotic leakage and those who did not. The expressed genes and enriched processes are involved in the different stages of wound healing. These provide therapeutic and diagnostic targets for patients at risk of anastomotic leakage

    Self-Dual N=8 Supergravity as Closed N=2(4) Strings

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    As open N=2 or 4 strings describe self-dual N=4 super Yang-Mills in 2+2 dimensions, the corresponding closed (heterotic) strings describe self-dual ungauged (gauged) N=8 supergravity. These theories are conveniently formulated in a chiral superspace with general supercoordinate and local OSp(8|2) gauge invariances. The super-light-cone and covariant-component actions are analyzed. Because only half the Lorentz group is gauged, the gravity field equation is just the vanishing of the torsion.Comment: 17 pg., (uuencoded dvi file; revision: forgot 1 stupid term in the last equation) ITP-SB-92-3
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