spectrometry to characterize the bead's movement along the thread. This is not the first switchable system to be developed. Fritz Vogtle of the University of Bonn, Germany, and coworkers have shown that catenanes (interlocking ring structures) can undergo reversible, light-induced E-to-Z isomerization. Roberto Ballardini of Istituto FRAE-CNR, Bologna, Italy; Vincenzo Balzani of the University of Bologna; Stoddart; and coworkers have photochemically "unthreaded" a pseudorotaxane (a rotaxane lacking stoppers). And Andrew C. Benniston and Anthony Harriman of the Center for Fast Kinetics Research at the University of Texas, Austin, have shown that lightinduced electron transfer can cause a bead to migrate along a thread. However, Kaifer and coworkers emphasize that their system differs from work by others: It is the first that can be switched controllably and reversibly by two different mechanisms. Chemistry professor Jonathan Lindsey of Carnegie Mellon University, who specializes in molecular electronics, notes, "Biology makes widespread use of structural changes in vision, ion gating, enzyme regulation, muscles, and flagella." The research by Kaifer and coworkers, he says, "represents an effort to learn how to build molecular devices where [such] structural changes can be effected in a controlled way." However, he adds, it would be difficult to use the molecular switch for fast computation because the switching times are slow. Benniston calls the molecular switch "certainly a very nice system," but he questions whether it should be considered truly reversible: The switching action is achieved with a large excess of protons, "unlike in nature, where it is done with ease using enzymes and one proton." Stoddart responds: "The addition of protons is as spontaneous as diffusioncontrolled processes can be, and the way by which the nitrogen atoms in the benzidine group become protonated is similar to what we find in the living world. I think here we have something that is comparable with enzymes." However, Kaifer, Stoddart, and coworkers concede that if systems like theirs are to be made useful for molecular electronics applications, supramolecular researchers must still "improve the molecular properties of [the] systems [and] find methods to 'wire' these novel molecules to the macroscopic world." Stu Borman
Africans spur vision of science-led development A vision of a new age of development in Africa led by science and technology—a vision that is uniquely African—was outlined last week by a small group of African scientists, educators, and analysts who met at a forum in Washington, D.C., sponsored by the American Association for the Advancement of Science (AAAS). About 100 U.S. and African participants discussed initiatives under way and innovations planned that aim to advance national science and technology policies and higher education reform efforts. The meeting was part of AAAS's Sub-Saharan Africa Program, supported by Carnegie Corp. of New York City. Keynote speaker for the meeting was entomologist Thomas Odhiambo, president and founder of the African Academy of Sciences, based in Nairobi, Kenya. Odhiambo is also the recently retired director of the International Center of Insect Physiology & Ecology in Nairobi. Odhiambo notes that the academy is helping the African National Congress in South Africa to create a science and technology policy for that nation. Academy officials met with representatives from relevant South African institutions and civic groups and have produced a draft report. However, Odhiambo's remarks focused on the upcoming establishment of an African Foundation for Research & Development. AFRAND is expected to be officially launched in July when a group of national science officials called the Roundtable of Science Advisers for Science-Led Development in Africa meets in Maputo, Mozambique, to sign its charter. Structurally similar to a hybrid of the U.S/s National Science Foundation (NSF) and National Institute of Standards & Technology, "AFRAND will take up the task of redirecting contemporary research infrastructures on the continent away from pure fundamental research" and toward "productive requirements and key social services," Odhiambo stresses. In other words, AFRAND's goal is to tie together science and technology and investment capital to create a real dimate for growth. The major aim is to establish something lacking in Africa—technology and science tied to entrepreneurial capital, with universities as the key element. Odhiambo tells C&EN that no site is set yet for AFRAND, but several nations will submit bids in July. Neither does he
Odhiambo: tie research to development know how much AFRAND will need for its first-year budget. But he says $20 million would do nicely, increasing after a few years to $100 million per year. Funding will be sought from private foundations, development banks, aid agencies, and other sources. The foundation will differ from NSF by "directly aiming to tie research to development." It will strongly emphasize building "linkages" between university scientists and managers in industry. And it will establish liaison offices to link African researchers with those in North and South America. What makes Odhiambo optimistic in the face of a continent largely beset by misery and plummeting economic indicators? In a word, sovereignty—the feeling that black Africa may be about to control its destiny. Generations ago, Africa lost millions of people to the slave trade and whole civilizations were wiped out, he notes. Native culture was further decimated when Europe colonized and imposed its values. Now for the first time, he believes, a genuinely African culture keyed to science and technology may emerge. However, skepticism is expressed by meeting participant Robert H. Maybury, a U.S. expert on science, technology, and development who worked for years in Africa. He says he has yet to see any signs university science programs are tied to development in Africa. But he hopes Odhiambo can turn that around. Wil Lepkowski MAY 16,1994 C&EN
9
