40,023 research outputs found

    Innovation and Economic Growth

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    This paper surveys the empirical evidence on the link between innovation and economic growth. It considers a number of different measures of innovation, such as R&D spending, patenting, and innovation counts, as well as the pervasive effect of technological spillovers between firms, industries, and countries. There are three main conclusions. The first is that innovation makes a significant contribution to growth. The second is there are significant spillovers between countries, firms and industries, and to a lesser extent from government-funded research. Third, that these spillovers tend to be localized, wit foreign economies gaining significantly less from domestic innovation than other domestic firms. This suggests that although technological 'catch-up' may act to equalize productivity across countries, the process is likely to be slow and uncertain, and require substantial domestic innovation effort.

    A spoonful of sugar: the application of glycopolymers in therapeutics

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    Glycopolymers, synthetic polymers displaying carbohydrate moieties, have been linked to many potential applications at the biology–chemistry interface. One area that holds particular promise is the employment of glycopolymers as vehicles for therapeutics or as therapeutics themselves. This review summarises some of the more prominent examples as well as those in the early stages of development

    Trends in Extreme Precipitation Events for the Northeastern United States 1948-2007

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    Comparative Behavior of \u3ci\u3ePyrellia Cyanicolor\u3c/i\u3e (Diptera: Muscidae) on the Moss \u3ci\u3eSplachnum Ampullaceum\u3c/i\u3e and on Substrates of Nutritional Value

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    (excerpt) Entomophily is commonly associated with flowering plants and their pollen vectors, but also occurs in other groups of plants. Among fungi, several genera of Phallaceae offer food rewards to calliphorid and muscid flies, which inadvertently disperse the fungal spores (Ingold 1964). Bryhn (1897) first noted a relationship between various species ofDiptera and members of the moss family Splachnaceae. The nature of this interaction has been the subject of much speculation (Bequaert 1921, Erlanson 1935, Crum et aI. 1972, Koponen and Koponen 1977), but no experimental evidence has been collected

    The early evolution of the solar system

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    The problems of relating collapse conditions in an interstellar cloud to a model of the primitive solar nebula are discussed. In such a nebula there is a radial force balance between gravity, the pressure gradient, and centrifugal forces due to the rotation. Approximate values are given for the combinations of temperature and density throughout the nebula, from a maximum of about 2000 K near the center to less than 200 K in the outer portion. These conditions are based upon the compression adiabats in the terminal stages of the collapse of an interstellar cloud. One general conclusion, of great importance for accumulation of bodies within the solar system, is that interstellar grains should not be completely evaporated at distances in the nebula beyond about one or more astronomical units

    Physics of Nonthermal Radio Sources

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    On December 3 and 4, 1962, the Goddard Institute for Space Studies, an office of the National Aeronautics and Space Administration, was host to an international group of astronomers and physicists who met to discuss the physics of nonthermal radio sources. This was the third in a continuing series of interdisciplinary meetings held at the Institute on topics which have a special bearing on the main lines of inquiry in the space program. The conference was organized by G. R. Burbidge of the University of California at San Diego and by L. Woltjer, then of the University of Leiden but temporarily at the Massachusetts Institute of Technology, and now of Columbia University

    Fourier and Beyond: Invariance Properties of a Family of Integral Transforms

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    The Fourier transform is typically seen as closely related to the additive group of real numbers, its characters and its Haar measure. In this paper, we propose an alternative viewpoint; the Fourier transform can be uniquely characterized by an intertwining relation with dilations and by having a Gaussian as an eigenfunction. This broadens the perspective to an entire family of Fourier-like transforms that are uniquely identified by the same dilation property and having Gaussian-like functions as eigenfunctions. We show that these transforms share many properties with the Fourier transform, particularly unitarity, periodicity and eigenvalues. We also establish short-time analogues of these transforms and show a reconstruction property and an orthogonality relation for the short-time transforms.Comment: 14 page
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