This issue of Limn explores new formations of infrastructure, publicness, and expertise.The contributions examine how new forms of expertise conceive the public and make claims in its name, how publics are making novel claims on experts (and claims to expertise), and how earlier norms and techniques of infrastructure provisioning are being adapted in the process.

This issue of Limn on “Ebola’s Ecologies” examines how the 2014 Ebola outbreak has put the norms, practices, and institutional logics of global health into question, and examines the new assemblages that are being forged in its wake.

Systemic risk has become a central topic of expert discussion and political debate amidst the financial crisis that began in 2008, but it also has resonances across many other domains in which catastrophic threats loom – including internet security, supply chain management, catastrophe insurance, and critical infrastructure protection. In this issue, we invited scholars to contribute genealogical and conceptual framings that inform critical inquiry into this increasingly important concept. The result is not a traditional collection of academic articles but a set of brief, preliminary reflections, prepared on short notice, that address a common set of questions, along with a handful of documents, links, images and videos that illustrate different aspects of the concept.

In this issue of Limn we examine the recent profusion of micro-technologies in the worlds of humanitarianism and development, some focused on fostering forms of social improvement, others claiming to alleviate suffering, and many seeking to accomplish both.