Nature is one of the world's most prestigious scientific journals, first published on 4 November 1869. It is the world's most highly cited interdisciplinary science journal. Most scientific journals are now highly specialized, and Nature is among the few journals (the other weekly journals Science and Proceedings of the National Academy of Sciences are also prominent examples) that still publish original research articles across a wide range of scientific fields. There are many fields of scientific research in which important new advances and original research are published as either articles or letters in Nature. Research scientists are the primary audience for the journal, but summaries and accompanying articles make many of the most important papers understandable for the general public and to scientists in other fields. Toward the front of each issue are editorials, news and feature articles on issues of general interest to scientists, including current affairs, science funding, business, scientific ethics and research breakthroughs. There are also sections on books and arts. The remainder of the journal consists mostly of research articles, which are often dense and highly technical. Because of strict limits on the length of articles, in many cases the printed text is actually a summary of the work in question with many details relegated to accompanying supplementary material on the journal's website. Registration not required.