Practical Implementation of Log-Scale Active Illumination Microscopy

Active illumination microscopy (AIM) is a method of redistributing dynamic range in a scanning microscope using real-time feedback to control illumination power on a sub-pixel time scale. We describe and demonstrate a fully integrated instrument that performs both feedback and image reconstruction. The image is reconstructed on a logarithmic scale to accommodate the dynamic range benefits of AIM in a single output channel. A theoretical and computational analysis of the influence of noise on active illumination feedback is presented, along with imaging examples illustrating the benefits of AIM. While AIM is applicable to any type of scanning microscope, we apply it here specifically to two-photon microscopy.National Institutes of Healt

Education Inequality, Human Capital Inequality and the Kuznets Curve

This paper develops an improved measure of human capital. Using a Mincer specification of human capital, the improved measure takes into consideration rates of returns to schooling, education quality, and school dropouts. The paper applies the improved measure to evaluate national and global human capital inequality and compares them with education inequality. Human capital Kuznets curves are evident when relative inequality measures are used while education Kuznets curves are found when absolute inequality measures are used. It is also found that while global education inequality has been declining over the past four decades, global human capital inequality remains largely steady.