3,425 research outputs found

    A construction of Frobenius manifolds with logarithmic poles and applications

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    A construction theorem for Frobenius manifolds with logarithmic poles is established. This is a generalization of a theorem of Hertling and Manin. As an application we prove a generalization of the reconstruction theorem of Kontsevich and Manin for projective smooth varieties with convergent Gromov-Witten potential. A second application is a construction of Frobenius manifolds out of a variation of polarized Hodge structures which degenerates along a normal crossing divisor when certain generation conditions are fulfilled.Comment: 46 page

    Optimized culture conditions for tissue explants of uterine leiomyoma

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    Background: Uterine leiomyomas are the most common benign tumours in women, which arise from smooth muscle cells of the uterine myometrium and usually are multicentric. In spite of their frequency pathogenesis is widely unknown, mainly due to the absence of a suitable model system. We describe the systematic optimization of culturing leiomyoma tissue explants in an economical and effective ex vivo system. Methods: Different concentrations of oxygen, different media, sera, hormones, and growth factor supplements were tested. Immunohistochemical stainings with antibodies against hormone receptors as well as specifying proliferation and apoptotic indices and real-time PCR were performed. Results: Main parameters for culturing myoma tissue explants were tested for finding an optimal protocol. Standard medium D-MEM-F12 in combination with the use of horse serum in a reduced concentration of 1% turned out to be optimal for these tissue cultures as well as the addition of estradiol and epidermal growth factor EGF to media. Reduced oxygen content in the incubator air showed no positive effect. Conclusions: For culturing tissue explants of uterine leiomyoma several conditions were optimized. The established tissue culture model allows examining the effects of known and potential therapeutic substances and the influence of immune competent cells in the process of tumour formation to find new targets for medical treatmen

    Orbital-assisted metal-insulator transition in VO2_{2}

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    We found direct experimental evidence for an orbital switching in the V 3d states across the metal-insulator transition in VO2_{2}. We have used soft-x-ray absorption spectroscopy at the V L2,3L_{2,3} edges as a sensitive local probe, and have determined quantitatively the orbital polarizations. These results strongly suggest that, in going from the metallic to the insulating state, the orbital occupation changes in a manner that charge fluctuations and effective band widths are reduced, that the system becomes more 1-dimensional and more susceptible to a Peierls-like transition, and that the required massive orbital switching can only be made if the system is close to a Mott insulating regime

    Social Value of Marine and Coastal Protected Areas in England and Wales.

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    The U.K. government is committed to establishing a coherent network of marine protected areas by 2012 and the recentMarine and Coastal Access Act, 2009 will designate marine conservation zones and provide wider access rights to the coast. To fulfill these goals, this article argues the need for a clearer, shared understanding of the social value of protected areas in creating new designations and managing existing ones. Although marine and coastal environments attract many people and are vitally important in terms of realized and potential social value, the majority of the public in the United Kingdom lacks understanding and awareness regarding them. Combined with this, the social value of marine and coastal protected areas (MCPAs) have been largely ignored relative to conservation and economics, with the latter invariably taking precedence in environmental policymaking. Social value reflects the complex, individual responses that people experience in a given place. Many reasons determine why one area is valued above another, and this research investigates the social value of MCPAs from a practitioner’s perspective through a series of interviews. Understanding why we “socially” value MCPAs will ultimately equip managers with an informed understanding of these spaces, influence management decisions, and, potentially, policymaking. This article defines social value in the context of MCPAs in England and Wales from a practitioner perspective, explores key concepts, and suggests possible improvements in decision-making

    Effective Rheology of Bubbles Moving in a Capillary Tube

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    We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

    Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV

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    Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 <pT,assoc<pT,trig< < p_{\rm{T}, assoc} < p_{\rm{T}, trig} < 5.0 GeV/cc is examined, to include correlations induced by jets originating from low momen\-tum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range η<0.9|\eta|<0.9. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton--parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p-Pb collisions. Further, the number scales in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/161
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