From Gizmodo: Why There’s More to Rising Sea Levels Than Melting Ice

Most simple explanations of climate change suggest that rising sea levels are a result of melting ice in the polar regions. While that’s true to an extent, there’s a simple piece of physics behind the rising waters that you might not have been made aware of. This video helps explain why it’s thermal expansion that’s the real problem—now we just need to work out how to stop it. [YouTube] More »


 

from Gizmodo

From Ars Technica: Viruses used in vaccines can recombine—and get virulent

The first successful vaccines, like Jenner’s smallpox vaccine and the first Salk vaccine against polio, were based on viruses that do not cause illness or severe symptoms. Vaccine development has since shifted largely to the use of proteins that are used by the disease-causing agents, but there are still some cases where a dead or attenuated virus is the most effective method of generating immunity.

The use of viruses for vaccines, however, has always come with a bit of a concern. When it comes to viruses, one-in-a-million events happen all the time, and evolution gives any viruses used in vaccines a lot to work with: many related viruses in the wild, and animal genomes that are littered with pieces of former viruses. Now, researchers have discovered a case where two different agricultural vaccines have recombined to create a new, virulent strain of the disease they were intended to prevent.

In poultry, a form of herpesvirus (gallid herpesvirus 1) causes a respiratory disease that is sometimes fatal; even if it doesn’t kill the animals, it causes a reduced egg production. As a result, several vaccines have been developed against the virus responsible, based on attenuated forms that do not cause serious illness. Three of these vaccines are approved for use in Australia: two based on viral strains that are present in Australia, and a third developed against a strain common in Europe.

 

from Ars Technica