Resumen de Brief points.

• The article presents news briefs related to science and research. Compared with people who sleep eight hours, five-hour snoozers produce 15 percent more gherlin, a hunger hormone, and 15 percent less leptin, an appetite suppressor. The driving force behind the evolution of the Homo species from Austrolopithecus may have been the ability to run long distances. An astrophysicist suggests that Jupiter's icy moon Europa could serve as a sensor of neutrinos a million times more energetic than those that can be caught on Earth. Antibodies from narcoleptic people induced a narcolepsylike symptom in the muscle of mice, suggesting that an autoimmune process plays a role in the sleep-wake disorder.