Solid-state growth of Si to produce planar surfaces

Paralleling the sophisticated control of Si and GaAs growth from fluid media, we demonstrate control of Si growth using a solid growth medium. Faceted dissolution pits were first produced in a Si substrate using standard photolithographic techniques and Al metallization. Si was then evaporated onto the cold structure, depositing as amorphous material. Upon heating, the amorphous Si migrated through the solid Al and grew rapidly in the faceted pits, typically refilling them flush with the surrounding substrate. Evidence that the rapid growth occurs only while the amorphous Si is dissolving into the Al is presented

The Effect of Virtual Civic Engagement on Crime: SeeClickFix in New Haven

Mobile virtual communities are an emerging space for improving social cohesiveness and promoting collective efficacy. The application SeeClickFix is a smartphone and web application developed in New Haven, Connecticut, where users report issues in their communities including non-violent crimes. These posts can be supported and commented on by other users and local government agencies acknowledge and address issues. The data are publicly available, providing a data-rich and transparent venue for monitoring the interaction of individuals with each other and city representatives. The purpose of our study is to look for correlations between SeeClickFix use and crime. We hypothesize that SeeClickFix activity reduces crime by increasing social cohesion and promoting collective efficacy. Preliminary analyses show that within each neighborhood, months with more SeeClickFix posts tend to have fewer crimes. In addition, the crime rate is lower after the creation of SeeClickFix relative to before. These data suggest that SeeClickFix use is correlated with reduced crime in New Haven. Further efforts are needed to establish if there is a causal relationship and if so by what mechanism. This work has the potential to suggest a method by which communities can increase transparency and reduce crime through an open data platform

Every Picture Tells a Story: The 2010 Round of Congressional Redistricting in New England

The United States Constitution requires that the number of representatives in Congress be reapportioned among the states based on a decennial census, and the U.S. Supreme Court ruled half a century ago that congressional districts within each state must be, as nearly as practicable, equal in population. However, the actual drawing of district lines for our national lower house and the methods employed for doing so are largely left to the individual states. Redistricting thus presents a fertile field for the comparative examination of state politics and political institutions