A pill taken once a week. A shot administered at home once a month. Even a jab given at a clinic every six months. In the next five to 10 years, these options may be available to prevent or treat H.I.V. Instead of drugs that must be taken daily, scientists are closing in on longer-acting alternatives — perhaps even a …

A Boeing engineer who went public last week with safety concerns about the company’s 787 Dreamliner told a Senate panel on Wednesday that he was concerned that shortcuts the company was taking would eventually lead to a crash if they continued unchecked. The engineer, Sam Salehpour, testified that in an attempt to address bottlenecks, Boeing introduced production shortcuts with the …

It was a brazen theft: thousands of gold bars and millions of dollars in bank notes stolen a year ago from Toronto’s international airport. On Wednesday, Canadian authorities announced the arrest of nine people, including an Air Canada employee, in connection with the theft of more than 20 million Canadian dollars, about $14.5 million, in gold bars and 2.5 million …