Scientists at the University of Cincinnati (UC) College of Medicine have discovered the cause of a deadly type of secondary stroke known as cerebral vasospasm.

Elephants learn to imitate sounds that are not typical of their species, the first known example after humans of vocal learning in a non-primate terrestrial mammal. The discovery, reported in today's Nature, further supports the idea that vocal learning is important for maintaining individual social relationships among animals that separate and reunite over time, like dolphins and whales, some birds, and bats.

A bacterium that lives in the human gut adaptively shifts more than a quarter of its genes into high gear when its host's diet changes from sugar to complex carbohydrates.

This adaptive mechanism not only allows the bacterial species to survive rapidly changing nutrient conditions but also helps maintain the functions and stability of the gut's highly complex microbial society, according to researchers at Washington University School of Medicine in St. Louis.

A research team based at Massachusetts General Hospital (MGH) has identified 80 new genes essential to the process of RNA interference (RNAi), a powerful new research tool for inactivating genes in plants or animals. They used the RNAi process itself to find new genes that participate in the gene-silencing mechanism, which someday may help to fight human disease. The report will appear in the journal Science and is receiving early online release on the Science Express website at http://www.sciencexpress.org.

After decades of laboratory work studying how animals evolve, researchers sometimes need to put on the hip waders, pull out the fishing net and go learn how their theory compares to the real world. According to a Stanford University School of Medicine study published in the March 25 issue of Science, Mother Nature is more predictable than lab experiments suggest.