1,100 research outputs found

    Power Converters of the Main Dipole and Quadrupole Magnet Strings of the Antiproton Decelerator at CERN

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    The two main power converters for the dipoles (D) and quadrupoles (Q) are presented as part of the complex power converter system of the Antiproton Decelerator. The operational requirements and the performance specifications for deceleration from 3.5 to 0.1 GeV/c are discussed. The layout and design of the power part, consisting of a 12-pulse thyristor rectifier and a switch-mode parallel active filter (AF), and of the precision regulation are described. The alternatives for integrating the AF into the current and voltage regulation loops are outlined. Problems encountered and results of tests are reported

    До проблеми вивчення весілля Шевченкового краю (за матеріалами передвесільної обрядовості)

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    While businesses may attract potential offenders and thus be conducive to disorder, the number of employees could offset this by exercising social control on offenders. This study uses data from different sources to test this expectation across 278 Dutch neighborhoods in the four largest cities of the Netherlands, using multivariate multilevel analysis to disentangle individual perception differences of disorder and neighborhood effects. Attention is paid to traditional explanations of disorder (i.e., poverty, residential mobility, and ethnic heterogeneity). Results show a positive relationship between business presence and neighborhood disorder. We do not find consistent results of the number of employees (i.e., bigger businesses are not always better or worse). Our research demonstrates that the presence of neighborhood businesses could rival the effects of social disorganization theory

    Different activation energies in glucose uptake in Saccharomyces cerevisiae DFY1 suggest two transport systems

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    AbstractThe analysis of initial glucose uptake in Saccharomyces cerevisiae at 25°, 20°, 15° and 10°C by computer-assisted nonlinear regression analysis predicts two transport systems. The first demonstrates Michaelis–Menten kinetics and the second shows first order behaviour. The activation energies of these two systems were calculated by the Arrhenius equation at four different growth phases, namely early exponential (EE), middle exponential (ME2), late exponential (LE) and early stationary (ES) with 2% glucose in the batch medium. The activation energies calculated from the Vm values in EE, ME, LE and ES growth phases were 15.8±1.7, 13.5±1.0, 15.1±0.8 and 13.5±0.7 kcal/mol. These values are in agreement with activation energies calculated for the first mechanism, facilitated diffusion, which is the mechanism deduced from countertransport experiments. The activation energies derived for the second transport system from the first order rate constants in cells grown to EE, ME2, LE and ES were 8.0±2.1, 8.1±1.3, 9.6±3.0 and 7.5±2.6 kcal/mol. These values are still significantly higher than for free diffusion of glucose in water and lower as predicted for passage of glucose through the lipid phase. Therefore, we assume in addition to carrier-mediated facilitated diffusion the entrance of glucose into the cell through a pore

    The Foundations of Human Pro-Social Behaviour: Some Economic Aspects

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    Pro-social behaviour has an economic foundation. Income rate, social discount rates, incentives and welfare motives force agents to act pro-socially. Pro-social behaviour is realized through the institution of social responsibility, which includes non-market coordination mechanism, altruism, social capital and trust. The nature of the institute of social responsibility and its components are described in the first part of the paper. The second part describes the conditions that promote pro-social behaviour and reflect the main features of the institute of social responsibility. In the third part we tested the hypothesis of the second part on the basis of a comparative analysis of pro-social behaviour in Russia and OECD countries. In the fourth part we summed up the conclusions of the study. The study found a direct connection between the pro-social behaviour, the level of trust, volunteer and charitable activities. For empirical testing of theoretical hypotheses we use sociological surveys data of WVS (2010-2014), ESS (2012). In this paper we evaluated the pro-social behaviour in Russia in comparison with OECD countries. We used the following indicators: positive expectations for the future, trust, participation in volunteer activities and charity. We found that pro-social activity is poorly implemented in Russia. The low level of per capita income, low level of interpersonal trust, weak development of volunteer and charitable activities and pessimistic expectations of the future - these are the key factors that reduce pro-social activity in Russia

    Evaluating the semantic web: a task-based approach

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    The increased availability of online knowledge has led to the design of several algorithms that solve a variety of tasks by harvesting the Semantic Web, i.e. by dynamically selecting and exploring a multitude of online ontologies. Our hypothesis is that the performance of such novel algorithms implicity provides an insight into the quality of the used ontologies and thus opens the way to a task-based evaluation of the Semantic Web. We have investigated this hypothesis by studying the lessons learnt about online ontologies when used to solve three tasks: ontology matching, folksonomy enrichment, and word sense disambiguation. Our analysis leads to a suit of conclusions about the status of the Semantic Web, which highlight a number of strengths and weaknesses of the semantic information available online and complement the findings of other analysis of the Semantic Web landscape

    Comparative genomics in chicken and Pekin duck using FISH mapping and microarray analysis

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    BACKGROUND: The availability of the complete chicken (Gallus gallus) genome sequence as well as a large number of chicken probes for fluorescent in-situ hybridization (FISH) and microarray resources facilitate comparative genomic studies between chicken and other bird species. In a previous study, we provided a comprehensive cytogenetic map for the turkey (Meleagris gallopavo) and the first analysis of copy number variants (CNVs) in birds. Here, we extend this approach to the Pekin duck (Anas platyrhynchos), an obvious target for comparative genomic studies due to its agricultural importance and resistance to avian flu. RESULTS: We provide a detailed molecular cytogenetic map of the duck genome through FISH assignment of 155 chicken clones. We identified one inter- and six intrachromosomal rearrangements between chicken and duck macrochromosomes and demonstrated conserved synteny among all microchromosomes analysed. Array comparative genomic hybridisation revealed 32 CNVs, of which 5 overlap previously designated "hotspot" regions between chicken and turkey. CONCLUSION: Our results suggest extensive conservation of avian genomes across 90 million years of evolution in both macro- and microchromosomes. The data on CNVs between chicken and duck extends previous analyses in chicken and turkey and supports the hypotheses that avian genomes contain fewer CNVs than mammalian genomes and that genomes of evolutionarily distant species share regions of copy number variation ("CNV hotspots"). Our results will expedite duck genomics, assist marker development and highlight areas of interest for future evolutionary and functional studies

    USTOPIA REQUIREMENTS THOUGHTS ON A USER-FRIENDLY SYSTEM FOR TRANSFORMATION OF PROGRAMS IN ABSTRACTO

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    Transformational programming is a program development method which is usually applied using 'pen and paper'. Since this requires a lot of clerical work (copying expressions, con- sistent substitution) which is tiresome and prone to error, some form of machine support is desirable. In this paper a number of systems are described that have already been built to this aim. Some of their shortcomings and limitations are identified. Based on experience with program transformation and transformation systems, a long list of features is given that would be useful in an 'utopian' transformation system. This list is presented using an orthogonal division of the problem area. A number of problems with the realisation of some aspects of our 'utopian' system are identified, and some areas for further research are indicated
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