Gated communities as club goods: segregation or social cohesion?

Gated communities are normally presented in highly negative terms, based on the common assumption that they contribute to social segregation. In contrast to received wisdom this paper argues that the theory of club goods can be used to understand gating as a response to both real and perceived issues of crime, vandalism and anti-social behaviour. We suggest that gating can help to foster social cohesion by involving a wide spectrum of communities and income groups to: reduce crime, protect parked vehicles, increase safety and enhance the local environment by preventing unsolicited entry. The paper explores through two case studies, how communities struggling with neighbourhood problems including crime are using gating as a way of improving their environment rather than abandoning poorer areas of the city to find a safer home in more residentially segregated better off neighbourhoods. If housing and planning policy makers are to take seriously a commitment to resident democracy and local participation, such concerns should not be dismissed out of hand as examples of 'isolationism' or 'particularistic consumerist interests'

Covariate Balance in Simple, Stratified and Clustered Comparative Studies

In randomized experiments, treatment and control groups should be roughly the same--balanced--in their distributions of pretreatment variables. But how nearly so? Can descriptive comparisons meaningfully be paired with significance tests? If so, should there be several such tests, one for each pretreatment variable, or should there be a single, omnibus test? Could such a test be engineered to give easily computed $p$-values that are reliable in samples of moderate size, or would simulation be needed for reliable calibration? What new concerns are introduced by random assignment of clusters? Which tests of balance would be optimal? To address these questions, Fisher's randomization inference is applied to the question of balance. Its application suggests the reversal of published conclusions about two studies, one clinical and the other a field experiment in political participation.Comment: Published in at http://dx.doi.org/10.1214/08-STS254 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Efficient multiple time scale molecular dynamics: using colored noise thermostats to stabilize resonances

Multiple time scale molecular dynamics enhances computational efficiency by updating slow motions less frequently than fast motions. However, in practice the largest outer time step possible is limited not by the physical forces but by resonances between the fast and slow modes. In this paper we show that this problem can be alleviated by using a simple colored noise thermostatting scheme which selectively targets the high frequency modes in the system. For two sample problems, flexible water and solvated alanine dipeptide, we demonstrate that this allows the use of large outer time steps while still obtaining accurate sampling and minimizing the perturbation of the dynamics. Furthermore, this approach is shown to be comparable to constraining fast motions, thus providing an alternative to molecular dynamics with constraints.Comment: accepted for publication by the Journal of Chemical Physic

Electron Magnetic Resonance

Contains research objectives and reports on one research project.Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E

You Never Can Tell

https://digitalcommons.library.umaine.edu/mmb-vp/3457/thumbnail.jp

Wait For Me

https://digitalcommons.library.umaine.edu/mmb-vp/5970/thumbnail.jp