When the Delta variant was dominant in the United States ... The data included in the study was collected before the Omicron wave in the United States, and before boosters were widely available.

Delta plus is related to the Delta, an existing variant of concern first identified in India last year that was responsible for the deadly second wave. But how realistic are these fears?

An curved arrow pointing right. Following is a transcript of the video. This is how scientists study tsunamis. The Delta Flume is a massive wave tank in the Netherlands. It's nearly 1,000- feet long.

theta waves and delta waves. The former are typically recorded when we’re in the process of falling asleep, whereas the latter two come about during sleep. Once we pass into the REM or rapid-eye ...