NEWS Clues to early life Conventional wisdom among geologists had held that oxygen in the ancient oceans was rare until the “great oxygenation event,” 2.4 to 2.2 billion years ago. But last year, UW-Madison geoscientists – using a high-resolution mass spectrometer – analyzed iron-bearing rocks from 3.2 billion years ago and found unmistakeable evidence of oxygen. They concluded its source must be the earliest known example of photosynthesis. “Once life gets oxygenic photosynthesis, the sky is the limit,” says Clark Johnson, professor of geoscience and a member of the NASA Astrobiology Institute. The study was funded by NASA. — Adapted from a story by David Tenenbaum
Uniting computer sciences and psychology What if a fusion of computer science and psychology could help us understand more about how people learn, making it possible to design ideal lessons? Computer sciences professor Jerry Zhu’s paper on “machine teaching” – a twist on the more familiar “machine learning” – won the Blue Sky Ideas Prize at the Computing Community Consortium. “The machine-teaching approach needs a good model of how the learner behaves – that is, how the learner’s behavior changes with different kinds of . . . experiences,” says Timothy T. Rogers, a professor of cognitive psychology and one of Zhu’s collaborators. The team includes computer science professors Michael Ferris, Bilge Mutlu and Stephen Wright, as well as psychology professor Martha Alibali and faculty from engineering and educational psychology. — Adapted from a story by Jennifer Smith
“Red flag” for lithium battery The material at the heart of the lithium ion batteries that power electric vehicles, laptop computers and smartphones may have untold environmental consequences. A new study by researchers at the University of Wisconsin-Madison and the University of Minnesota explored the effects of the compound nickel manganese cobalt oxide (NMC) on the common soil and sediment bacterium Shewanella oneidensis. Exposed to the compound, the bacterium (which is found worldwide and is a good toxicity indicator species), exhibited inhibited growth and respiration. “Nickel is dirt cheap. It’s pretty good at energy storage,” says UW-Madison chemistry professor Robert J. Hamers, who led the researchers. “It is also toxic. So is cobalt. As far as we know, this is the first study that’s looked at the environmental impact of these materials.” — Adapted from a story by Terry Devitt
L&S Annual Review 2015-2016
The Annual Review for the College of Letters & Science at the University of Wisconsin-Madison.