27,132 research outputs found

    The Determinants of National Innovative Capacity

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    Motivated by differences in R&D productivity across advanced economies, this paper presents an empirical examination of the determinants of country-level production of international patents. We introduce a novel framework based on the concept of national innovative capacity. National innovative capacity is the ability of a country to produce and commercialize a flow of innovative technology over the long term. National innovative capacity depends on the strength of a nation's common innovation infrastructure (cross-cutting factors which contribute broadly to innovativeness throughout the economy), the environment for innovation in its leading industrial clusters, and the strength of linkages between these two areas. We use this framework to guide our empirical exploration into the determinants of country-level R&D productivity, specifically examining the relationship between international patenting (patenting by foreign countries in the United States) and variables associated with the national innovative capacity framework. While acknowledging important measurement issues arising from the use of patent data, we provide evidence for several findings. First, the production function for international patents is surprisingly well-characterized by a small but relatively nuanced set of observable factors, including R&D manpower and spending, aggregate policy choices such as the extent of IP protection and openness to international trade, and the share of research performed by the academic sector and funded by the private sector. As well, international patenting productivity depends on each individual country's knowledge stock.' Further, the predicted level of national innovative capacity has an important impact on more downstream commercialization and diffusion activities (such as achieving a high market share of high-technology export markets). Finally, there has been convergence among OECD countries in terms of the estimated level of innovative capacity over the past quarter century.

    Immunofluorescent Examination of Biopsies from Long-Term Renal Allografts

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    Immunofluorescent examination of open renal biopsies revealed clear-cut glomerular localization of immunoglobulins not related clearly to the quality of donor-recipient histocompatibility in 19 of 34 renal allografts. The biopsies were obtained 18 to 31 months after transplantations primarily from related donors with a variable quality of histocompatibility match. IgG was the predominant immunoglobulin class fixed in 13 biopsies, and IgM in six. The pattern of immunoglobulin deposition was linear, connoting anti-GBM antibody in four of the 19; it was granular and discontinuous, connoting antigen–antibodycomplex deposits, in 13. An immune process may affect glomeruli of renal allografts by mechanisms comparable to those that cause glomerulonephritis in native kidneys. The transplant glomerulonephritis may represent a persistence of the same disease that originally destroyed the host kidneys or the consequence of a new humoral antibody response to allograft antigens. © 1970, Massachusetts Medical Society. All rights reserved

    Few-fermion systems in one dimension: Ground- and excited-state energies and contacts

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    Using the lattice Monte Carlo method, we compute the energy and Tan's contact in the ground state as well as the first excited state of few- to many-fermion systems in a one-dimensional periodic box. We focus on unpolarized systems of N=4,6,...,12 particles, with a zero-range interaction, and a wide range of attractive couplings. In addition, we provide extrapolations to the infinite-volume and thermodynamic limits.Comment: 8 pages, 12 figures; published versio

    Severity of disease and risk of malignant change in hereditary multiple exostoses. A genotype-phenotype study

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    We performed a prospective genotype-phenotype study using molecular screening and clinical assessment to compare the severity of disease and the risk of sarcoma in 172 individuals (78 families) with hereditary multiple exostoses. We calculated the severity of disease including stature, number of exostoses, number of surgical procedures that were necessary, deformity and functional parameters and used molecular techniques to identify the genetic mutations in affected individuals. Each arm of the genotype-phenotype study was blind to the outcome of the other. Mutations EXT1 and EXT2 were almost equally common, and were identified in 83% of individuals. Non-parametric statistical tests were used. There was a wide variation in the severity of disease. Children under ten years of age had fewer exostoses, consistent with the known age-related penetrance of this condition. The severity of the disease did not differ significantly with gender and was very variable within any given family. The sites of mutation affected the severity of disease with patients with EXT1 mutations having a significantly worse condition than those with EXT2 mutations in three of five parameters of severity (stature, deformity and functional parameters). A single sarcoma developed in an EXT2 mutation carrier, compared with seven in EXT1 mutation carriers. There was no evidence that sarcomas arose more commonly in families in whom the disease was more severe. The sarcoma risk in EXT1 carriers is similar to the risk of breast cancer in an older population subjected to breast-screening, suggesting that a role for regular screening in patients with hereditary multiple exostoses is justifiable. ©2004 British Editorial Society of Bone and Joint Surgery

    Finite-difference distributions for the Ginibre ensemble

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    The Ginibre ensemble of complex random matrices is studied. The complex valued random variable of second difference of complex energy levels is defined. For the N=3 dimensional ensemble are calculated distributions of second difference, of real and imaginary parts of second difference, as well as of its radius and of its argument (angle). For the generic N-dimensional Ginibre ensemble an exact analytical formula for second difference's distribution is derived. The comparison with real valued random variable of second difference of adjacent real valued energy levels for Gaussian orthogonal, unitary, and symplectic, ensemble of random matrices as well as for Poisson ensemble is provided.Comment: 8 pages, a number of small changes in the tex

    Hotspots of corruption: Applying a problem-oriented approach to preventing corruption in the public sector

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    “The final publication is available at Springer via http://dx.doi.org/10.1057/sj.2013.38.". © Palgrave Macmillan, a division of Macmillan Publishers Ltd 2013Some places have no crime and some have a lot, and thus we study hotspots. Corruption is structured differently to crime, but hotspots still are notable. The difference is that hotspots are not places but clusters of activity. This article analyses corruption cases from New York City to explore a way of identifying such clusters. Seventy-two cases were coded according to features that represent the elements of the crime triangle: offender and motivation, target and opportunity, and place and ability. Multidimensional scaling revealed three groups of cases, exhibiting different patterns of corrupt activity. Group one involved politicians involved in high value financial corruption. Group two primarily involved supervisors who created opportunities involving procurement and contracts. Group three involved inspectors, particularly in the infrastructure sector, who were involved with low value bribes to violate regulations. Each is discussed in relation to situational crime prevention principles to develop possible strategies for prevention

    Monomial integrals on the classical groups

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    This paper presents a powerfull method to integrate general monomials on the classical groups with respect to their invariant (Haar) measure. The method has first been applied to the orthogonal group in [J. Math. Phys. 43, 3342 (2002)], and is here used to obtain similar integration formulas for the unitary and the unitary symplectic group. The integration formulas turn out to be of similar form. They are all recursive, where the recursion parameter is the number of column (row) vectors from which the elements in the monomial are taken. This is an important difference to other integration methods. The integration formulas are easily implemented in a computer algebra environment, which allows to obtain analytical expressions very efficiently. Those expressions contain the matrix dimension as a free parameter.Comment: 16 page

    Observation of discrete energy levels in a quantum confined system

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    Low temperature scanning tunneling microscope images and spectroscopic data have been obtained on subnanometer size Pb clusters fabricated using the technique of buffer layer assisted growth. Discrete energy levels were resolved in current-voltage characteristics as current peaks rather than current steps. Distributions of peak voltage spacings and peak current heights were consistent with Wigner-Dyson and Porter-Thomas distributions respectively, suggesting the relevance of random matrix theory to the description of the electronic eigenstates of the clusters. The observation of peaks rather than steps in the current-voltage characteristics is attributed to a resonant tunneling process involving the discrete energy levels of the cluster, the tip, and the states at the interface between the cluster and the substrate surface.Comment: 4 pages, 4 figure

    Distribution of the spacing between two adjacent avoided crossings

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    We consider the frequency at which avoided crossings appear in an energy level structure when an external field is applied to a quantum chaotic system. The distribution of the spacing in the parameter between two adjacent avoided crossings is investigated. Using a random matrix model, we find that the distribution of these spacings is well fitted by a power-law distribution for small spacings. The powers are 2 and 3 for the Gaussian orthogonal ensemble and Gaussian unitary ensemble, respectively. We also find that the distributions decay exponentially for large spacings. The distributions in concrete quantum chaotic systems agree with those of the random matrix model.Comment: 11 page
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