This paper estimates the impact of corruption and poor bureaucratic quality on firm productivity for a unique dataset with firm-specific data of more than 900 firms over 12 years for Ghana, Kenya and Tanzania. We first discuss why poor bureaucratic quality and, especially, corruption are expected to have negative impacts on firm productivity. We then employ Data Envelopment Analysis to estimate firm productivity and pooled OLS and Tobit regression analysis to estimate the effects of corruption and bureaucratic quality on firm productivity. We find that less productive firms are more likely to engage in corrupt activities; both poor bureaucratic quality and corruption reduce firm productivity; and corruption has a greater negative impact on productivity. . We would like to thank the participants in the 2009 Midwest Economic Association Meetings and an anonymous referee for their helpful comments. We are responsible for any remaining errors.

Novel psychoactive substances (NPS) refer to synthetic compounds or derivatives of more widely known substances of abuse that have emerged over the last two decades. Case reports suggest that users combine substances to achieve desired psychotropic experiences while reducing dysphoria and unpleasant somatic effects. However, the pattern of combining NPS has not been studied on a large scale. Here, we show that posts discussing NPS describe combining nootropics with sedative-hypnotics and stimulants with plant hallucinogens or psychiatric medications. Discussions that mention sedative-hypnotics most commonly also mention hallucinogens and stimulants. We analyzed 20 years of publicly available posts from Lycaeum, an Internet forum dedicated to sharing information about psychoactive substance use. We used techniques from natural language processing and machine learning to identify NPS and correlate patterns of co-mentions of substances across posts. We found that conversations mentioning synthetic hallucinogens tended to divide into those mentioning hallucinogens derived from amphetamine and those derived from ergot. Conversations that mentioned synthetic hallucinogens tended not to mention plant hallucinogens. Conversations that mention bath salts commonly mention sedative-hypnotics or nootropics while more canonical stimulants are discussed with plant hallucinogens and psychiatric medications. All types of substances are frequently compared to MDMA, DMT, cocaine, or atropine when trying to describe their effects. Our results provide the largest analysis to date of online descriptions of patterns of polysubstance use and further demonstrate the utility of social media in learning about trends in substance use. We anticipate this work to lead to a more detailed analysis of the knowledge contained online about the patterns of usage and effects of novel psychoactive substances.

Microvascular endothelial cell heterogeneity and its relationship to hemodynamics remains poorly understood due to a lack of sufficient methods to examine these parameters in vivo at high resolution throughout an angiogenic network. The availability of surrogate markers for functional vascular proteins, such as green fluorescent protein, enables expression in individual cells to be followed over time using confocal microscopy, while photoacoustic microscopy enables dynamic measurement of blood flow across the network with capillary-level resolution. We combined these two non-invasive imaging modalities in order to spatially and temporally analyze biochemical and biomechanical drivers of angiogenesis in murine corneal neovessels. By stimulating corneal angiogenesis with an alkali burn in Tie2-GFP fluorescent-reporter mice, we evaluated how onset of blood flow and surgically-altered blood flow affects Tie2-GFP expression. Our study establishes a novel platform for analyzing heterogeneous blood flow and fluorescent reporter protein expression across a dynamic microvascular network in an adult mammal.

This paper uses the Data Envelopment Analysis (DEA) technique to estimate the technical efficiency of firms in Ghana across six manufacturing industries during 1991-2002. We observe that manufacturing firms in Ghana are significantly less efficient than their counterparts in other countries. In addition, we find that firm characteristics such as size, age, foreign ownership, and the mix of labor and capital used during the production process have positive effects on firm efficiency. These results have implications for Ghana's import-substitution industrialization and foreign investment policies. We would like to thank an anonymous referee for comments and suggestions. We are responsible for any remaining errors.

Using a translog stochastic production frontier and maximum likelihood estimation method, we estimate fundraising efficiency and examine the determinants of fundraising efficiency in public charitable organizations in the United States. Our study shows that organizational size has a positive impact on fundraising efficiency and government grants have a negative impact on fundraising efficiency. We also show that charities that allocate more resources on fundraising related labor, as compared with fundraising-related materials and equipments, are more efficient in fundraising. These findings provide important managerial implications for public charities. Copyright © 2010 John Wiley & Sons, Ltd.