The evolving capabilities of rhodopsin-based genetically encoded voltage indicators.

Protein engineering over the past four years has made rhodopsin-based genetically encoded voltage indicators a leading candidate to achieve the task of reporting action potentials from a population of genetically targeted neurons in vivo. Rational design and large-scale screening efforts have steadily improved the dynamic range and kinetics of the rhodopsin voltage-sensing domain, and coupling these rhodopsins to bright fluorescent proteins has supported bright fluorescence readout of the large and rapid rhodopsin voltage response. The rhodopsin-fluorescent protein fusions have the highest achieved signal-to-noise ratios for detecting action potentials in neuronal cultures to date, and have successfully reported single spike events in vivo. Given the rapid pace of current development, the genetically encoded voltage indicator class is nearing the goal of robust spike imaging during live-animal behavioral experiments.

Politics by number: Indicators as social pressure in international relations

© 2014, Midwest Political Science Association.The ability to monitor state behavior has become a critical tool of international governance. Systematic monitoring allows for the creation of numerical indicators that can be used to rank, compare, and essentially censure states. This article argues that the ability to disseminate such numerical indicators widely and instantly constitutes an exercise of social power, with the potential to change important policy outputs. It explores this argument in the context of the United States' efforts to combat trafficking in persons and find evidence that monitoring has important effects: Countries are more likely to criminalize human trafficking when they are included in the U.S. annual Trafficking in Persons Report, and countries that are placed on a "watch list" are also more likely to criminalize. These findings have broad implications for international governance and the exercise of soft power in the global information age.