3,374 research outputs found

    Informing Consumers About Themselves

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    Consumers make mistakes. Imperfect information and imperfect rationality lead to misperception of benefits and costs associated with a product. As a result, consumers might fail to maximise their preferences in product choice or product use. A proposed taxonomy of consumer mistakes draws attention to a less-studied category of mistakes: use-pattern mistakes – mistakes about how the consumer will use the product. Use-pattern mistakes are prevalent. Sellers respond strategically to use-pattern mistakes by redesigning their products, contracts and pricing schemes. These strategic design responses often exacerbate the welfare costs associated with consumer mistakes. From a policy perspective, focusing on disclosure regulation, the importance of use-pattern mistakes requires more, and better, use-pattern disclosure. In particular, sellers should be required to provide individualised use-pattern information

    Holographic U(1)_A and String Creation

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    We analyze the resolution of the U(1)_A problem in the Sakai-Sugimoto holographic dual of large N_c QCD at finite temperature. It has been shown that in the confining phase the axial symmetry is broken at order 1/N_c, in agreement with the ideas of Witten and Veneziano. We show that in the deconfined phase the axial symmetry remains unbroken to all orders in 1/N_c. In this case the breaking is due to instantons which are described by spacelike D0-branes, in agreement with 'tHooft's resolution. The holographic dual of the symmetry breaking fermion condensate is a state of spacelike strings between the D0-brane and the flavor D8-branes, which result from a spacelike version of the string creation effect. In the intermediate phase of deconfinement with broken chiral symmetry the instanton gas approximation is possibly regulated in the IR, which would imply an eta' mass-squared of order exp(-N_c).Comment: 18 pages, 19 figures, minor change

    Antimicrobial and anti-inflammatory activity of chitosan-alginate nanoparticles: a targeted therapy for cutaneous pathogens.

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    Advances in nanotechnology have demonstrated potential application of nanoparticles (NPs) for effective and targeted drug delivery. Here we investigated the antimicrobial and immunological properties and the feasibility of using NPs to deliver antimicrobial agents to treat a cutaneous pathogen. NPs synthesized with chitosan and alginate demonstrated a direct antimicrobial activity in vitro against Propionibacterium acnes, the bacterium linked to the pathogenesis of acne. By electron microscopy (EM) imaging, chitosan-alginate NPs were found to induce the disruption of the P. acnes cell membrane, providing a mechanism for the bactericidal effect. The chitosan-alginate NPs also exhibited anti-inflammatory properties as they inhibited P. acnes-induced inflammatory cytokine production in human monocytes and keratinocytes. Furthermore, benzoyl peroxide (BP), a commonly used antiacne drug, was effectively encapsulated in the chitosan-alginate NPs and demonstrated superior antimicrobial activity against P. acnes compared with BP alone while demonstrating less toxicity to eukaryotic cells. Together, these data suggest the potential utility of topical delivery of chitosan-alginate NP-encapsulated drug therapy for the treatment of dermatologic conditions with infectious and inflammatory components

    Universality and Clustering in 1+1 Dimensional Superstring-Bit Models

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    We construct a 1+1 dimensional superstring-bit model for D=3 Type IIB superstring. This low dimension model escapes the problems encountered in higher dimension models: (1) It possesses full Galilean supersymmetry; (2) For noninteracting polymers of bits, the exactly soluble linear superpotential describing bit interactions is in a large universality class of superpotentials which includes ones bounded at spatial infinity; (3) The latter are used to construct a superstring-bit model with the clustering properties needed to define an SS-matrix for closed polymers of superstring-bits.Comment: 11 pages, Latex documen

    Quark mass and condensate in HQCD

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    We extend the Sakai-Sugimoto holographic model of QCD (HQCD) by including the scalar bi-fundamental "tachyon" field in the 8-brane-anti-8-brane probe theory. We show that this field is responsible both for the spontaneous breaking of the chiral symmetry, and for the generation of (current algebra) quark masses, from the point of view of the bulk theory. As a by-product we show how this leads to the Gell-Mann- Oakes-Renner relation for the pion mass.Comment: 23 pages, 7 figures; v2: corrected typos in eqs. (4.3), (4.4), (4.5), (4.9) and (4.11), and corrected figures 3, 4, 5 and 6; v3: section 5.3 on the pion mass rewritten in a clearer way, version published in JHE

    Threading plasmonic nanoparticle strings with light

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    This work is licensed under a Creative Commons Attribution 4.0 International License.-- et al.Nanomaterials find increasing application in communications, renewable energies, electronics and sensing. Because of its unsurpassed speed and highly tuneable interaction with matter, using light to guide the self-assembly of nanomaterials can open up novel technological frontiers. However, large-scale light-induced assembly remains challenging. Here we demonstrate an efficient route to nano-assembly through plasmon-induced laser threading of gold nanoparticle strings, producing conducting threads 12±2nm wide. This precision is achieved because the nanoparticles are first chemically assembled into chains with rigidly controlled separations of 0.9nm primed for re-sculpting. Laser-induced threading occurs on a large scale in water, tracked via a new optical resonance in the near-infrared corresponding to a hybrid chain/rod-like charge transfer plasmon. The nano-thread width depends on the chain mode resonances, the nanoparticle size, the chain length and the peak laser power, enabling nanometre-scale tuning of the optical and conducting properties of such nanomaterials.We acknowledge financial support from EPSRC grants EP/G060649/1, EP/K028510/1 and EP/L027151/1, ERC grants LINASS 320503 and ASPiRe 240629, and project FIS2010-19609-C02-01 from the Spanish Ministry of Science and Innovation. J.S.B. acknowledges the School of Physical Science, University of Cambridge, for the funding of the transmission electron microscope. S.K. acknowledges funding from the Biochemical Society (Krebs Memorial Scholarship) and the Cambridge Commonwealth Trust.Peer Reviewe

    Observing Single Molecules Complexing with Cucurbit[7]uril through Nanogap Surface-Enhanced Raman Spectroscopy.

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    In recent years, single-molecule sensitivity achievable by surface-enhanced Raman spectroscopy (SERS) has been widely reported. We use this to investigate supramolecular host-guest chemistry with the macrocyclic host cucurbit[7]uril, on a few-to-single-molecule level. A nanogap geometry, comprising individual gold nanoparticles on a planar gold surface spaced by a single layer of molecules, gives intense SERS signals. Plasmonic coupling between the particle and the surface leads to strongly enhanced optical fields in the gap between them, with single-molecule sensitivity established using a modification of the well-known bianalyte method. Changes in the Raman modes of the host molecule are observed when single guests included inside its cavity internally stretch it. Anisotropic intermolecular interactions with the guest are found which show additional distinct features in the Raman modes of the host molecule.The authors acknowledge funding from Walters-Kundert Trust, EPSRC (EP/K028510/1, EP/G060649/1, EP/ H007024/1, ERC LINASS 320503), an ERC starting investigator grant (ASPiRe 240629), EU CUBiHOLE grant and the Defence Science and Technology Laboratory (DSTL). S.K. thanks Krebs Memorial Scholarship (The Biochemical Society) and Cambridge Commonwealth Trust for funding.This is the author accepted manuscript. The final version is available from ACS via http://dx.doi.org/10.1021/acs.jpclett.5b0253
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