4,553 research outputs found

    Scalable squeezed light source for continuous variable quantum sampling

    Full text link
    We propose a novel squeezed light source capable of meeting the stringent requirements of continuous variable quantum sampling. Using the effective χ2\chi_2 interaction induced by a strong driving beam in the presence of the χ3\chi_3 response in an integrated microresonator, our device is compatible with established nanophotonic fabrication platforms. With typical realistic parameters, squeezed states with a mean photon number of 10 or higher can be generated in a single consistent temporal mode at repetition rates in excess of 100MHz. Over 15dB of squeezing is achievable in existing ultra-low loss platforms

    Include medical ethics in the Research Excellence Framework

    Get PDF
    The Research Excellence Framework of the Higher Education Funding Council for England is taking place in 2013, its three key elements being outputs (65% of the profile), impact (20%), and “quality of the research environment” (15%). Impact will be assessed using case studies that “may include any social, economic or cultural impact or benefit beyond academia that has taken place during the assessment period.”1 Medical ethics in the UK still does not have its own cognate assessment panel—for example, bioethics or applied ethics—unlike in, for example, Australia. Several researchers in medical ethics have reported to the Institute of Medical Ethics that during the internal preliminary stage of the Research Excellence Framework several medical schools have decided to include only research that entails empirical data gathering. Thus, conceptual papers and ethical analysis will be excluded. The arbitrary exclusion of reasoned discussion of medical ethics issues as a proper subject for medical research unless it is based on empirical data gathering is conceptually mistaken. “Empirical ethics” is, of course, a legitimate component of medical ethics research, but to act as though it is the only legitimate component suggests, at best, a partial understanding of the nature of ethics in general and medical ethics in particular. It also mistakenly places medicine firmly on only one side of the science/humanities “two cultures” divide instead of in its rightful place bridging the divide. Given the emphasis by the General Medical Council on medical ethics in properly preparing “tomorrow’s doctors,” we urge medical schools to find a way of using the upcoming Research Excellence Framework to highlight the expertise residing in their ethicist colleagues. We are confident that appropriate assessment will reveal work of high quality that can be shown to have social and cultural impact and benefit beyond academia, as required by the framework

    A model for gelation with explicit solvent effects: Structure and dynamics

    Full text link
    We study a two-component model for gelation consisting of ff-functional monomers (the gel) and inert particles (the solvent). After equilibration as a simple liquid, the gel particles are gradually crosslinked to each other until the desired number of crosslinks has been attained. At a critical crosslink density the largest gel cluster percolates and an amorphous solid forms. This percolation process is different from ordinary lattice or continuum percolation of a single species in the sense that the critical exponents are new. As the crosslink density pp approaches its critical value pcp_c, the shear viscosity diverges: η(p)∌(pc−p)−s\eta(p)\sim (p_c-p)^{-s} with ss a nonuniversal concentration-dependent exponent.Comment: 6 pages, 9 figure

    Variations in multiple sclerosis practice within Europe - Is it time for a new treatment guideline?

    Get PDF
    In the past 5 years, the combination of developments in diagnostic strategy and approval of new disease-modifying therapies has provided an opportunity to achieve dramatic improvements in patient outcomes in multiple sclerosis (MS). However, across Europe there are several factors that may prevent patients from receiving the best therapy at the appropriate time, and there is variation among countries in terms of which of these factors are most relevant. Here, we review current MS clinical practices in a number of countries in the European Union to identify differences regarding initiation of treatment in patients with clinically isolated syndrome or relapsing-remitting MS, and differences in the timing of treatment switch or escalation. While recognizing that policy is not static in any country, we believe that patients' interests would be better served if a European treatment guideline was developed. Such a guideline could both inform and be informed by national policies, facilitating the dissemination of best clinical practice internationally.info:eu-repo/semantics/publishedVersio

    Nonlinear Coupling of Linearly Uncoupled Resonators

    Full text link
    We demonstrate a system composed of two resonators that are coupled solely through a nonlinear interaction, and where the linear properties of each resonator can be controlled locally. We show that this class of dynamical systems has peculiar properties with important consequences for the study of classical and quantum nonlinear optical phenomena. As an example we discuss the case of dual-pump spontaneous four-wave mixing.Comment: 4 Figure

    DDFT calibration and investigation of an anisotropic phase-field crystal model

    Full text link
    The anisotropic phase-field crystal model recently proposed and used by Prieler et al. [J. Phys.: Condens. Matter 21, 464110 (2009)] is derived from microscopic density functional theory for anisotropic particles with fixed orientation. Further its morphology diagram is explored. In particular we investigated the influence of anisotropy and undercooling on the process of nucleation and microstructure formation from atomic to the microscale. To that end numerical simulations were performed varying those dimensionless parameters which represent anisotropy and undercooling in our anisotropic phase-field crystal (APFC) model. The results from these numerical simulations are summarized in terms of a morphology diagram of the stable state phase. These stable phases are also investigated with respect to their kinetics and characteristic morphological features.Comment: It contain 13 pages and total of 7 figure
    • 

    corecore