Models of structure formation based on cold dark matter predict that most of the small dark matter haloes that first formed at high redshift would have merged into larger systems by the present epoch. Substructure in present-day haloes preserves the remains of these ancient systems, providing the only direct information we may ever have about the low-mass end of the power spectrum. I describe s...

In 1997, 6 years after the World Wide Web became accessible to the public, the Proceedings of the National Academy of Sciences launched its website, heralding our entry into the Internet age and the expeditious dissemination of our scientific content worldwide (see Infographic). Toward the end of the last millennium, we redesigned the website to improve user experience and rebranded the journal...

The Arboretum’s 75th AnniversAry seminAr explored the history and future of restoration—both science and practice. Under the supervision of Joy Zedler, Botany 950 students traced the development of key ecological concepts through history. Under Paul Zedler’s guidance, Environmental Studies 992 students brought their interdisciplinary approaches to bear on where the Arboretum could make its grea...

Dedicated to Professor H. M. Srivastava on the Occasion of his Seventieth Birth Anniversary

Dedicated to Professor H. M. Srivastava on the Occasion of his Seventieth Birth Anniversary

Dedicated to Professor H. M. Srivastava on the Occasion of his Seventieth Birth Anniversary