6,447 research outputs found

    Is the Elephant Stepping on its Trunk? The Problem of India's Unbalanced Growth

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    It is often assumed that recent success in the high-technology software industry will lead India's development. However, evidence suggest that basic manufacturing industry is stagnant. This paper proposes a mechanism that ties these two trends together. A big-push type of model, featuring linkages between firms, demand spill-over, and technology choice is elaborated. By imposing different cost structures on the manufacturing and high-technology industries the model describes outcome in terms of distribution between sectors. It is found that a policy which promotes a high-technology sector can have negative effects on the manufacturing industry as well as aggregate income. Directing resources towards infrastructure, on the other hand, benefits all sectors and increases aggregate income. The results from the model are found to correspond with the recent development pattern in India.Industrialization; India; Industrial Structure

    Non-Gaussian Velocity Distributions in Optical Lattices

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    We present a detailed experimental study of the velocity distribution of atoms cooled in an optical lattice. Our results are supported by full-quantum numerical simulations. Even though the Sisyphus effect, the responsible cooling mechanism, has been used extensively in many cold atom experiments, no detailed study of the velocity distribution has been reported previously. For the experimental as well as for the numerical investigation, it turns out that a Gaussian function is not the one that best reproduce the data for all parameters. We also fit the data to alternative functions, such as Lorentzians, Tsallis functions and double Gaussians. In particular, a double Gaussian provides a more precise fitting to our results.Comment: Final published version with 12 pages and 12 figure

    Parametric Evaluation of Thin, Transonic Circulation-Control Airfoils

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    Wind-tunnel tests were conducted in the NASA Langley Transonic Dynamics Tunnel on a 6 percent-thick, elliptical circulation-control airfoil with upper-surface and lower-surface blowing capability. Results for elliptical Coanda trailing-edge geometries, biconvex Coanda trailing-edge geometries, and leading-edge geometries are reported. Results are presented at subsonic and transonic Mach numbers of 0.3 and 0.8, respectively. When considering one fixed trailing-edge geometry, for both the subsonic and transonic conditions it was found that the [3.0:1] ratio elliptical Coanda surface with the most rounded leading-edge [03] performed favorably and was determined to be the best compromise between comparable configurations that took advantage of the Coanda effect. This configuration generated a maximum. (Delta)C(sub 1) = 0.625 at a C(sub mu) = 0.06 at M = 0.3, alpha = 6deg. This same configuration generated a maximum (Delta)C(sub 1) = 0.275 at a C(sub mu) = 0.0085 at M = 0.8, alpha = 3deg

    American exceptionalism in a new light : a comparison of intergenerational earnings mobility in the Nordic countries, the United Kingdom and the United States

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    We develop methods and employ similar sample restrictions to analyse differences in intergenerational earnings mobility across the United States, the United Kingdom, Denmark, Finland, Norway and Sweden. We examine earnings mobility among pairs of fathers and sons as well as fathers and daughters using both mobility matrices and regression and correlation coefficients. Our results suggest that all countries exhibit substantial earnings persistence across generations, but with statistically significant differences across countries. Mobility is lower in the U.S. than in the U.K., where it is lower again compared to the Nordic countries. Persistence is greatest in the tails of the distributions and tends to be particularly high in the upper tails: though in the U.S. this is reversed with a particularly high likelihood that sons of the poorest fathers will remain in the lowest earnings quintile. This is a challenge to the popular notion of ’American exceptionalism’. The U.S. also differs from the Nordic countries in its very low likelihood that sons of the highest earners will show downward ’long-distance’ mobility into the lowest earnings quintile. In this, the U.K. is more similar to the U.S

    American exceptionalism in a new light : a comparison of intergenerational earnings mobility in the Nordic countries, the United Kingdom and the United States

    Get PDF
    We develop methods and employ similar sample restrictions to analyse differences in intergenerational earnings mobility across the United States, the United Kingdom, Denmark, Finland, Norway and Sweden. We examine earnings mobility among pairs of fathers and sons as well as fathers and daughters using both mobility matrices and regression and correlation coefficients. Our results suggest that all countries exhibit substantial earnings persistence across generations, but with statistically significant differences across countries. Mobility is lower in the U.S. than in the U.K., where it is lower again compared to the Nordic countries. Persistence is greatest in the tails of the distributions and tends to be particularly high in the upper tails: though in the U.S. this is reversed with a particularly high likelihood that sons of the poorest fathers will remain in the lowest earnings quintile. This is a challenge to the popular notion of ’American exceptionalism’. The U.S. also differs from the Nordic countries in its very low likelihood that sons of the highest earners will show downward ’long-distance’ mobility into the lowest earnings quintile. In this, the U.K. is more similar to the U.S..Intergenerational mobility ; earnings inequality ; long-run earnings

    Limited antigenic diversity of Plasmodium falciparum apical membrane antigen 1 supports the development of effective multi-allele vaccines

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    BackgroundPolymorphism in antigens is a common mechanism for immune evasion used by many important pathogens, and presents major challenges in vaccine development. In malaria, many key immune targets and vaccine candidates show substantial polymorphism. However, knowledge on antigenic diversity of key antigens, the impact of polymorphism on potential vaccine escape, and how sequence polymorphism relates to antigenic differences is very limited, yet crucial for vaccine development. Plasmodium falciparum apical membrane antigen 1 (AMA1) is an important target of naturally-acquired antibodies in malaria immunity and a leading vaccine candidate. However, AMA1 has extensive allelic diversity with more than 60 polymorphic amino acid residues and more than 200 haplotypes in a single population. Therefore, AMA1 serves as an excellent model to assess antigenic diversity in malaria vaccine antigens and the feasibility of multi-allele vaccine approaches. While most previous research has focused on sequence diversity and antibody responses in laboratory animals, little has been done on the cross-reactivity of human antibodies.MethodsWe aimed to determine the extent of antigenic diversity of AMA1, defined by reactivity with human antibodies, and to aid the identification of specific alleles for potential inclusion in a multi-allele vaccine. We developed an approach using a multiple-antigen-competition enzyme-linked immunosorbent assay (ELISA) to examine cross-reactivity of naturally-acquired antibodies in Papua New Guinea and Kenya, and related this to differences in AMA1 sequence.ResultsWe found that adults had greater cross-reactivity of antibodies than children, although the patterns of cross-reactivity to alleles were the same. Patterns of antibody cross-reactivity were very similar between populations (Papua New Guinea and Kenya), and over time. Further, our results show that antigenic diversity of AMA1 alleles is surprisingly restricted, despite extensive sequence polymorphism. Our findings suggest that a combination of three different alleles, if selected appropriately, may be sufficient to cover the majority of antigenic diversity in polymorphic AMA1 antigens. Antigenic properties were not strongly related to existing haplotype groupings based on sequence analysis.ConclusionsAntigenic diversity of AMA1 is limited and a vaccine including a small number of alleles might be sufficient for coverage against naturally-circulating strains, supporting a multi-allele approach for developing polymorphic antigens as malaria vaccines

    RDF and PIDs for INSPIRE: a missing item in ARE3NA

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    The presentation will outline intermediate results of a study in the context of geospatial data sharing across borders and at European level. The study is aiming to develop a common approach to generating common RDF schemas for representing INSPIRE data and metadata, as well as guidelines for the governance of persistent identifiers (PIDs). These are important elements for enabling the re-use of INSPIRE data in other sectors, in particular in e-government. The results of the study may feed into a proposal for additional encoding rules and guidelines for INSPIRE and will be performed in close collaboration with the INSPIRE Maintenance and Implementation Group and the ISA Programme’s Spatial Information and Services Working Group.JRC.H.6-Digital Earth and Reference Dat

    Mixing between high velocity clouds and the Galactic halo

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    In the Galactic halo, metal-bearing Galactic halo material mixes into high velocity clouds (HVCs) as they hydrodynamically interact. This interaction begins long before the clouds completely dissipate and long before they slow to the velocity of the Galactic material. In order to make quantitative estimates of the mixing efficiency and resulting metal enrichment of HVCs, we made detailed two- and three-dimensional simulations of cloud-interstellar medium interactions. Our simulations track the hydrodynamics and time-dependent ionization levels. They assume that the cloud originally has a warm temperature and extremely low metallicity while the surrounding medium has a high temperature, low density, and substantial metallicity, but our simulations can be generalized to other choices of initial metallicities. In our simulations, mixing between cloud and halo gas noticeably raises the metallicity of the high velocity material. We present plots of the mixing efficiency and metal enrichment as a function of time.open0
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