When searching for co-authors, the "AND" operator seems to be broken as it yields no results.
For example, go to http://plosone-branch:8080 and go to Advanced Search.
In the Author Name field, enter "han", then add another author field and enter "boyden". Leave the Search for: radio button at the default option, "Any of these authors". Click the Search button and you will see a single result - note that both Han and Boyden are listed as authors.
Now, in the query edit field at the top of the search results page, change the "OR" to an "AND". Click go. You will get no results! This also is what happens if you go back to the Advanced Search page and select the "Search for: All of these" option radio button.
