Chemistry Professor Charles Sharpless is the co-author of two recently published articles. The first, entitled “Photooxidation-induced changes in optical, electrochemical, and photochemical properties of humic substances,” was co-authored with colleagues from U.C. Berkeley and the Swiss Federal Institute of Technology (ETH Zurich) and appears in the current issue of the American Chemical Society journal, Environmental Science & Technology. A research article, it focuses on how prolonged exposure to solar radiation alters the photochemical and electrochemical properties of natural dissolved organic matter, ubiquitous brown “stuff” in surface waters that participates in many aspects of environmental aquatic chemistry. The second article, entitled “The importance of charge-transfer interactions in determining chromophoric dissolved organic matter (CDOM) optical and photochemical properties,” was co-authored with Professor Neil Blough (Chemistry, U. MD College Park). This was an invited review for the Royal Society of Chemistry’s journal, Environmental Sciences: Processes and Impacts, formerly The Journal of Environmental Modeling. The review, containing 247 references, deals with the optical and photochemical properties of natural dissolved organic matter, how those properties are related, and the relevance of these relationships for current research in environmental photochemistry. The article is currently in advance electronic format and will be published later this year in a specially-themed journal issue devoted to aquatic photochemical processes.