3,039 research outputs found

    Implementation of a Quantum Algorithm to Solve Deutsch's Problem on a Nuclear Magnetic Resonance Quantum Computer

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    We demonstrate the use of an NMR quantum computer based on the pyrimidine base cytosine, and the implementation of a quantum algorithm to solve Deutsch's problem.Comment: 16 pages including 6 figures. Minor clarifications as requested by the referee plus updated references. Journal of Chemical Physics, in press (expected publication date August 1st 1998

    Note about a second "evidence" for a WIMP annual modulation

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    This note, with its five questions, is intended to contribute to a clarification about a claimed "evidence" by the DAMA group of an annual modulation of the counting rate of a Dark Matter NaI(Tl) detector as due to a neutralino (SUSY-LSP) Dark Matter candidate.Comment: LaTex, 3 pages, 2 figure

    Health Insurance Competition: The Effect of Group Contracts

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    In countries like the US and the Netherlands health insurance is provided by private firms. These private firms can offer both individual and group contracts. The strategic and welfare implications of such group contracts are not well understood. Using a Dutch data set of about 700 group health insurance contracts over the period 2007-2008, we estimate a model to determine which factors explain the price of group contracts. We find that groups that are located close to an insurers’ home turf pay a higher premium than other groups. This finding is not consistent with the bargaining argument in the literature as it implies that concentrated groups close to an insurer’s home turf should get (if any) a larger discount than other groups. A simple Hotelling model, however, does explain our empirical results.health insurance;health-plan choice;managed competition

    On the Teneurin track: a new synaptic organization molecule emerges

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    To achieve proper synaptic development and function, coordinated signals must pass between the pre- and postsynaptic membranes. Such transsynaptic signals can be comprised of receptors and secreted ligands, membrane associated receptors, and also pairs of synaptic cell adhesion molecules. A critical open question bridging neuroscience, developmental biology, and cell biology involves identifying those signals and elucidating how they function. Recent work in Drosophila and vertebrate systems has implicated a family of proteins, the Teneurins, as a new transsynaptic signal in both the peripheral and central nervous systems. The Teneurins have established roles in neuronal wiring, but studies now show their involvement in regulating synaptic connections between neurons and bridging the synaptic membrane and the cytoskeleton. This review will examine the Teneurins as synaptic cell adhesion molecules, explore how they regulate synaptic organization, and consider how some consequences of human Teneurin mutations may have synaptopathic origins

    Resonant tunneling magnetoresistance in epitaxial metal-semiconductor heterostructures

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    We report on resonant tunneling magnetoresistance via localized states through a ZnSe semiconducting barrier which can reverse the sign of the effective spin polarization of tunneling electrons. Experiments performed on Fe/ZnSe/Fe planar junctions have shown that positive, negative or even its sign-reversible magnetoresistance can be obtained, depending on the bias voltage, the energy of localized states in the ZnSe barrier and spatial symmetry. The averaging of conduction over all localized states in a junction under resonant condition is strongly detrimental to the magnetoresistance

    Drosophila Importin-α2 Is Involved in Synapse, Axon and Muscle Development

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    Nuclear import is required for communication between the cytoplasm and the nucleus and to enact lasting changes in gene transcription following stimuli. Binding to an Importin-α molecule in the cytoplasm is often required to mediate nuclear entry of a signaling protein. As multiple isoforms of Importin-α exist, some may be responsible for the entry of distinct cargoes rather than general nuclear import. Indeed, in neuronal systems, Importin-α isoforms can mediate very specific processes such as axonal tiling and communication of an injury signal. To study nuclear import during development, we examined the expression and function of Importin-α2 in Drosophila melanogaster. We found that Importin-α2 was expressed in the nervous system where it was required for normal active zone density at the NMJ and axonal commissure formation in the central nervous system. Other aspects of synaptic morphology at the NMJ and the localization of other synaptic markers appeared normal in importin-α2 mutants. Importin-α2 also functioned in development of the body wall musculature. Mutants in importin-α2 exhibited errors in muscle patterning and organization that could be alleviated by restoring muscle expression of Importin-α2. Thus, Importin-α2 is needed for some processes in the development of both the nervous system and the larval musculature

    How the reliability of external competences shapes the modularization strategies of industrialized construction firms

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    Firms modularize as they move into industrialized construction. Prior research highlights the importance of their modularization strategies, arguing that firms can either build the competence for modularization internally or can source them externally. To understand what shapes a firm’s choice to use external competences in its modularization strategy, we studied three leading construction firms. In this multiple case study, Alpha, Beta and Gamma are leaders in Asian markets, using reinforced concrete solutions in high-rise industrialized construction. Where external competences are available, our analyses show the work firms do to make them reliable and that their choice to use external competences is shaped by their reliability. Alpha modularized in a context with little available external competences, so it built new competences in-house; Beta chose to use the externally available manufacturing and assembly competences, using standards, remote monitoring and control of product architectures to make them reliable for their use in modularization; Gamma had available competences in the external context and initially sought to use them, but reliability concerns led to it modularizing by acquiring the firms to bring these competences in-house. Our contribution is to show how ensuring the reliability of external competences shapes modularization strategies. Further, we have identified actions that firms can adopt to make external competences reliable through: (1) use of international standards, (2) quality control procedures, (3) control of product architectures, and 4) acquisition of external competences. We provide implications for practitioners and policy makers seeking to transition to industrialized construction; and discuss new areas for research

    Management of In-Transit Malignant Melanoma

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