Scientists Find New Way to Produce Hydrogen

Scientists at Penn State University and the Virginia Commonwealth University have discovered a way to produce hydrogen by exposing selected clusters of aluminum atoms to water. The findings are important because they demonstrate that it is the geometries of these aluminum clusters, rather than solely their electronic properties, that govern the proximity of the clusters' exposed active sites. The proximity of the clusters' exposed sites plays an important role in affecting the clusters' reactions with water. The results could open up a new area of research, not only related to splitting water, but also to breaking the bonds of other molecules as well. The team investigated the reactions of water with individual aluminum clusters by combining them under controlled conditions in a custom-designed flow-reactor. They found that a water molecule will bind between two aluminum sites in a cluster as long as one of the sites behaves like a Lewis acid, a positively charged center that wants to accept an electron, and the other behaves like a Lewis base, a negatively charged center that wants to give away an electron. The Lewis-acid aluminum binds to the oxygen in the water and the Lewis-base aluminum dissociates a hydrogen atom. If this process happens a second time with another set of two aluminum sites and a water molecule, then two hydrogen atoms are available, which then can join to become hydrogen gas (H₂).

Native Lizards Evolve to Escape Invasive Fire Ants

Penn State biologist Tracy Langkilde has shown that native fence lizards in the southeastern United States are adapting to potentially fatal invasive fire-ant attacks by developing behaviors that enable them to escape from the ants, as well as by developing longer hind legs, which can increase the effectiveness of this behavior. Not only does this finding provide biologists with an example of evolution in action, but it also provides wildlife managers with knowledge that they can use to develop plans for managing invasive species. Langkilde conducted an experiment in which she compared the responses to fire ant attacks of lizards that were collected from four different sites: one that had not yet been invaded by fire ants and ones that were invaded by fire ants 23, 54, and 68 years ago. Her goal was to determine whether the amount of time since invasion influences the ways in which lizards respond to attacks. She found that the lizards from sites that have been invaded the longest were more likely than the lizards from sites that have not yet been invaded to twitch vigorously to remove ants and then to run away from the mound. She also found that the lizards with the longest hind legs were the most successful at getting away from ants.

Hair of Tasmanian Tiger Yields Genes of Extinct Species

Scientists at Penn State and their international team of colleagues have revealed all the genes that the exotic Tasmanian Tiger inherited only from its mother. The research marks the first successful sequencing of genes from this carnivorous marsupial, which looked like a large tiger-striped dog and became extinct in 1936. The research also opens the door to the widespread, nondestructive use of museum specimens to learn why mammals become extinct and how extinctions might be prevented. The team extracted and sequenced DNA from the hair of two specimens, not from bone, which has been used in previous studies of extinct species. The new gene sequences permitted the team to accurately determine how the Tasmanian Tiger is related to other marsupials.