Bostonia: The Boston University Alumni Magazine. Volume 10

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Bostonia: The Boston University Alumni Magazine. Volume 15

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Visible Light-Driven O 2 Reduction by a Porphyrin–Laccase System

International audienceSeveral recent studies have shown that the combination of photosensitizers with metalloenzymes can support a light-driven multielectron reduction of molecules such as CO 2 or HCN. Here we show that the association of the zinc tetramethylpyridinium porphyrin (ZnTMPyP 4+) photo-sensitizer with the multicopper oxidase (MCO) laccase allows to link the oxidation of an organic molecule to the four electrons reduction of dioxygen into water. The enzyme is photoreduced within minutes with porphyrin/enzyme ratio as low as 1:40. With a 1:1 ratio, the dioxygen consumption rate is 1.7 μmol L −1 s −1. Flash photolysis experiments support the formation of the triplet excited state of ZnTMPyP 4+ which reduces the enzyme to form a radical cation of the porphyrin with a k ET ≈ 10 7 s −1 M −1. The long-lived triplet excited state of the ZnTMPyP 4+ (τ 0 = 0.72 ms) accounts for a substantial electron-transfer quantum yield, ϕ ET = 0.35. Consequently, the enzyme-dependent photo-oxidation of the electron donor occurs with a turnover of 8 min −1 for the one-electron oxidation process, thereby supporting the suitability of such enzyme/sensitizer hybrid systems for aerobic photodriven transformations on substrates. This study is the first example of a phorphyrin-sensitized four-electron reduction of an enzyme of the MCO family, leading to photoreduction of dioxygen into water

Management Activity and Program Performance: Gender as Management Capital

Do men and women manage differently? Do their efforts have different impacts on public program performance? Building from a formal treatment of public management and performance, this study investigates how the interaction of gender and management strategies influences organizational performance. Focusing on several hundred public organizations and their top managers over a three-year period, the analysis maps the gender question onto Mark Moore's distinction among managing upward toward political principals, downward toward organizational agents, and outward toward the networked environment. Findings indicate that women and men as top managers have different performance impacts, and these impacts vary by managerial function as well