Government-Assisted Housing and Electoral Participation in New York City, 2000-2001

For a representative democracy to function optimally, citizens from all walks of life should have equal chances to express their preferences through the electoral process. In practice, we know that the actual rate of electoral participation varies greatly depending on individual circumstances and social settings. Better off, better educated, non-Hispanic white citizens are more likely to vote; poor, less educated, and minority individuals are much less likely to do so. Gaining a better understanding of why and how this might be so is crucial for moving toward a more democratic polity

Vacuum-UV photoabsorption imaging of laser produced plasmas

Complementaiy to the existing VUV/soft X-ray spectroscopic systems, a VUV photoabsorption imaging optical system has been developed.The technique consists in passing a pulsed VUV beam, tuned to an atomic/ionic resonance, through a laser plasma plume and recording the transmitted light or shadowgram. A first optical set-up was designed and built as proof of principle to validate the photoabsorption technique. The promising results obtained, as well as the limitations of the system lead, to the design and fabrication of a new system with improved flux collection, probe beam quality, spatial and spectral resolution. The design o f both systems was done with the aid of a ray tracing code, and the calculated performances from the simulations were compared to experimental measurements. Time and space resolved distributions o f atomic calcium, Ca+, Ca2+ equivalent width were measured using the respective 3p-3d resonances, and information on the plasma expansion dynamics was extracted and compared with an expansion model. With the absolute cross section known, maps of equivalent width could be converted to maps of column density NL; this was achievable when using the 3p-3d Ca+ resonance at 37.43 nm and the 5p-5d Ba+ resonance at 46.7 nm

Tracking ground state Ba+ ions in an expanding laser–plasma plume using time-resolved vacuum ultraviolet photoionization imaging

We report results from a study of the integrated column density and expansion dynamics of ground-state-selected Ba+ ions in a laser–plasma plume using a new experimental system—VPIF (vacuum-ultraviolet photoabsorption imaging facility). The ions are tracked by recording the attenuation of a pulsed and collimated vacuum ultraviolet beam, tuned to the 5p–6d inner-shell resonance of singly ionized barium, as the expanding plasma plume moves across it. The attenuated beam is allowed to fall on a CCD array where the spatial distribution of the absorption is recorded. Time-resolved ion velocity and integrated column density maps are readily extracted from the photoionization images

Union Effects on Productivity, Profits, and Growth - Has the Long Run Arrived?

This article interprets literature examining union effects on economic performance. Production function studies indicate small overall union impacts on productivity; positive effects, where they exist, appear to result from management response to decreased profit expectations and from a natural selection process. Lower profitability among unionized firms is well established; more interesting is the possibility that unions appropriate quasi rents deriving from long-lived tangible and intangible capital. the connection between unions, investment behavior, and productivity growth emerges as a particularly fruitful line of empirical inquiry, although it does not encourage a sanguine view of unionism\u27s long-run impact

Entropy zero area preserving diffeomorphisms of S2S^2

In this paper we formulate and prove a structure theorem for area preserving diffeomorphisms of genus zero surfaces with zero entropy. As an application we relate the existence of faithful actions of a finite index subgroup of the mapping class group of a closed surface $\Sigma_g$ on $S^2$ by area preserving diffeomorphisms to the existence of finite index subgroups of bounded mapping class groups $MCG(S, \partial S)$ with non-trivial first cohomology.Comment: 88 pages, 4 figure