Top stories: the appendix’s secret seeds, earthquake warnings, and a halted heart repair trial

(left to right): B. A. KILLINGER ET AL. SCIENCE TRANSLATIONAL MEDICINE (2018); ROBERTO CIGNA; SPL/SCIENCE SOURCE

Seeds of Parkinson’s disease may hide in the appendix

We tend to ignore the appendix unless it gets inflamed and needs cutting out. But a new study suggests this enigmatic organ in the gut harbors a supply of a brain-damaging protein involved in Parkinson’s disease—even in healthy people. The study is the largest yet to find that an appendectomy early in life can decrease a person’s risk of Parkinson’s or delay its onset.

California’s new earthquake warnings deliver critical seconds of notice

The U.S. Geological Survey has released ShakeAlert, its earthquake early warning system. If all goes as planned, a dense network of seismometers on the U.S. West Coast will detect the first waves of an earthquake and relay warnings to first responders, power companies, transit agencies, and in later iterations, the public. But the initial, ambitious promises of detecting distant earthquakes far in advance have been tempered by the complex, unpredictable ways faults fracture. Even the mere seconds of warning the system is now able to produce are considered a major victory.

Federal officials pause trial testing stem cells for heart disease

This week, federal officials paused a clinical study on the potential of stem cells to repair the heart, citing the news that Harvard University plans to retract 31 papers from cardiac researcher Piero Anversa, many of which were foundational to the trial. Some critics of Anversa’s work say studies like the now-halted trial should never have started, given long-standing questions about how—and whether—the cells Anversa identified might repair heart tissue.

This ‘two-faced’ membrane can create electricity—from nothing but salty water

Researchers have developed a “two-faced” membrane with different properties on either side capable of harvesting electric energy via osmosis, in which dissolved particles move spontaneously to balance their concentrations. In this case, the membrane helps efficiently shuttle salt ions from seawater into less salty freshwater, generating an electric current along the way.

New generation of ‘flow batteries’ could eventually sustain a grid powered by the sun and wind

With the rise of wind and solar power, energy companies are looking for batteries to keep the power flowing when the sun doesn’t shine and the wind fails. Giant devices called flow batteries use tanks of electrolyte capable of storing enough electricity to power thousands of homes for many hours. But most flow batteries rely on vanadium, a somewhat rare and expensive metal, and alternatives are short-lived and toxic. Last week, researchers reported overcoming many of these drawbacks with a potentially cheap, long-lived, and safe flow battery.