Detecting gravitational lensing cosmic shear from samples of several galaxies using two-dimensional spectral imaging

Studies of weak gravitational lensing by large-scale structures require the measurement of the distortions introduced to the shapes of distant galaxies at the few percent level by anisotropic light deflection along the line of sight. To detect this signal on 1-10 arcmin scales in a particular field, accurate measurements of the correlations between the shapes of order 1000-10000 galaxies are required. This large-scale averaging is required to accommodate the unknown intrinsic shapes of the background galaxies, even with careful removal of systematic effects. Here an alternative is discussed. If it is possible to measure accurately the detailed dynamical structure of the background galaxies, in particular rotating disks, then it should be possible to measure directly the cosmic shear distortion, as it generally leads to a non-self-consistent rotation curve. Narrow spectral lines and excellent two-dimensional spatial resolution are required. The ideal lines and telescope are CO rotational transitions and the Atacama Large Millimeter Array (ALMA) respectively.Comment: 12 pages, 4 figures, Expected to appear in ApJ Letters Vol. 570, 10 May 2002. Replaced with final proof version correcting minor typo

Grenswaarden voor het N- en P-gehalte in vaste mest

The variation and limiting values of the N and P content of solid livestock manure were determined from the composition of manure that was transported from 2008 to 2010 as registered by the Dutch Regulation Service. The realibility of the data was evaluated on the basis of N- and P excreted by livestock and manure volumes

Energy-Productivity Convergence Across Developed and Developing Countries in 10 Manufacturing Sectors

This paper provides an empirical analysis of energy-productivity convergence across 56 developed and developing countries, in 10 manufacturing sectors, for the period 1971 to 1995. We find that, except for the non-ferrous metals sector, cross-country differences in absolute energy-productivity levels tend to decline, particularly in the less energy-intensive industries. Testing for the catch-up hypothesis using panel data confirms that in all manufacturing sectors energy-productivity growth is, in general, relatively high in countries that initially lag behind in terms of energy-productivity performance seem to be persistent; convergence is found to be country-specific rather than global, with countries converging to different steady states and several failing to catch up. Finally, we find that country-specific factors, such as energy price and investment ratio, do explain the observed cross-country differences in energy-productivity performance, but only to a very limited extent. Hence, further research is needed to identify what accounts for the observed persistence in cross-country energy-productivity differentials

Economic Impacts of Cultural Diversity in the Netherlands: Productivity, Utility, and Sorting

This paper identifies the impact of cultural diversity on local economies, by explaining spatial disparities in wages and housing prices across Dutch cities using unique individual panel data of homeowners during the period 1999 and 2008. We distinguish between the effects of spatial sorting based on individual heterogeneity, interactions-based productivity effects, and consumer amenities while controlling for interactions between the labor and housing market. In line with previous literature, we find a positive effect of cultural diversity on average housing prices. After controlling for spatial sorting, the effect of cultural diversity on housing prices is negative. The negative impact of cultural diversity on local housing markets is likely driven by a causal effect between the presence of immigrants and neighborhood quality that outweighs a positive effect of immigrant-induced diversity in consumption goods. © 2013, Wiley Periodicals, Inc

On the size and shape of excluded volume polymers confined between parallel plates

A number of recent experiments have provided detailed observations of the configurations of long DNA strands under nano-to-micrometer sized confinement. We therefore revisit the problem of an excluded volume polymer chain confined between two parallel plates with varying plate separation. We show that the non-monotonic behavior of the overall size of the chain as a function of plate-separation, seen in computer simulations and reproduced by earlier theories, can already be predicted on the basis of scaling arguments. However, the behavior of the size in a plane parallel to the plates, a quantity observed in recent experiments, is predicted to be monotonic, in contrast to the experimental findings. We analyze this problem in depth with a mean-field approach that maps the confined polymer onto an anisotropic Gaussian chain, which allows the size of the polymer to be determined separately in the confined and unconfined directions. The theory allows the analytical construction of a smooth cross-over between the small plate-separation de Gennes regime and the large plate-separation Flory regime. The results show good agreement with Langevin dynamics simulations, and confirm the scaling predictions.Comment: 15 pages, 3 figure