Twenty enzyme loci were studied in 44 Illinois populations of Oenothera biennis; four were polymorphic. Most of the variation was distributed between populations. Fifty-nine percent of the populations had one genotype, 27% two genotypes and the remaining 16% from three to five genotypes; the average was 1.50. The proportion of genetic diversity present in single populations is.38 of that presen...

Cook stoves that produce biochar as well as heat for cooking could help mitigate indoor air pollution from cooking fires and could enhance local soils, while their potential reductions in carbon (C) emissions and increases in soil C sequestration could offer access to C market financing. We use system dynamics modeling to (i) investigate the climate change impact of prototype and refined biocha...

This thesis explores "meaningfulness" in videogames. Academics, journalists, and others who write about games often discuss the concept of meaning yet seldom define it clearly. I am focusing on a variation of this topic: what it means for a gaming experience to be meaningful--literally: full of meaning. Meaningfulness, as I define it, refers to the quality a videogame has when one considers it ...

T he 2014 John Bates Clark Medal of the American Economic Association was awarded to Matthew Gentzkow of the University of Chicago Booth School of Business. The citation recognized Matt’s “fundamental contributions to our understanding of the economic forces driving the creation of media products, the changing nature and role of media in the digital environment, and the effect of media on educa...