The New York Times has published a bunch more subject headings to the Linked Data Cloud. I wrote about this last November when the NYT released 5000 person/place/organization names as subject headings (or, as I noted then, you can think of them as tags.) These subject headings are those that the NYT Open blog describes as “subject descriptors” — keywords related to article content instead of proper nouns. This release includes 498 of the most commonly-used subject headers, which, like the names, are mapped to DBPedia and/or Freebase. The NYT hopes to eventually release all 3,500 of its subject descriptors.
You can browse through all the available subject headings (the descriptors and the proper nouns) at http://data.nytimes.com/. Look for the alphabetical browsing links in the middle of the page. I looked through the Ds and the first one I found was DNA (Deoxyribonucleic Acid) at http://data.nytimes.com/26507891352660881440. This page of information shows the first and most recent use of the subject descriptor, Freebase and DBPedia links, and an associated article count. There’s also a “scope note,” that explains exactly what the subject heading covers. In this case the scope is “Used for any coverage that focuses on D.N.A. — whether in research, forensic science, genetics, etc.”
For details about using these headings in an article search, visit the Search API documentation. There’s also an API request tool for experimenting with searches without having to use an API key or build queries in a URL; here’s an example search for the DNA subject heading.