31,257 research outputs found
Innovation and Economic Growth
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.
The early evolution of the solar system
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
Solar models in relation to terrestrial climatic variations
The possibility is discussed of occasional larger changes in the state of the sun, lasting for some millions of years, which might be responsible for producing more drastic changes in earth's climate, called ice ages
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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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 Actions and Feelings Questionnaire in Autism and Typically Developed Adults
Open access via Springer Compact Agreement We are grateful to Simon Baron-Cohen and Paula Smith of the Cambridge Autism Centre for the use of the ARC database in distributing the questionnaire, to all participants for completing it, to Eilidh Farquar for special efforts in distributing the link and to Gemma Matthews for advice on using AMOS 23. JHGW is supported by the Northwood Trust.Peer reviewedPublisher PD
Physics of Nonthermal Radio Sources
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
Band Crossing and Signature Splitting in Odd Mass fp Shell Nuclei
Structure of two sets of mirror nuclei: 47V - 47Cr and 49Cr - 49Mn, as well
as 49V and 51Mn, is studied using the projected shell model. Their yrast
spectra are described as an interplay between the angular momentum projected
states around the Fermi level which carry different intrinsic K-quantum
numbers. The deviations from a regular rotational sequence are attributed to
band crossing and signature splitting, which are usually discussed in heavy
nuclear systems. Our results agree reasonably with experimental data, and are
comparable with those from the full shell model calculations.Comment: 3 figures, submitted to Nucl. Phys.
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