Derek Lowe, in signing off for the Labor Day weekend: "It’s easy to forget that scientific research is (like many other things) one of the brightly colored dabs of paint that make up the very thin veneer we call civilization.

"There’s a lot of stuff underneath, and a lot of it is ugly. It’s the Hobbesian state of nature down there, a struggle for food and water and territory. Being able to think all day for a living - well, that’s a huge outlier exception to the way the vast majority of human beings have had to live their lives. What’s happened to New Orleans has been a terrible reminder of this truth. It’s taken just a few days for the Lord of the Flies to become mayor in a special election there, and the same thing could happen anywhere else on Earth.

"Let’s hope that it never happens to us. Be grateful that you have the weekend to enjoy in peace and sanity, and consider giving something to help pull those people out of the water, out of the mud, and back to the dry land of the 21st century..."