A Simple Model of the Rise and Fall of Civilizations.

The literature on the fall of civilizations spans from the archaeology of early state societies to the history of the 20th century. Explanations for the fall of civilizations abound, from general extrinsic causes (drought, warfare) to general intrinsic causes (intergroup competition, socioeconomic inequality, collapse of trade networks) and combinations of these, to case-specific explanations for the specific demise of early state societies. Here, we focus on ancient civilizations, which archaeologists typically define by a set of characteristics including hierarchical organization, standardization of specialized knowledge, occupation and technologies, and hierarchical exchange networks and settlements.

Liparis aphylla (Malaxideae, Orchidaceae), a new leafless record from Peru.

Liparis aphylla G.A.Romero & Garay was previously known only from two herbarium specimens collected in 1945 and 1977 in Ecuador and Colombia, respectively.

Books average previous decade of economic misery.

For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates.

A rapid method for assessing social versus independent interest in health issues: a case study of 'bird flu' and 'swine flu'.

Effective communication strategies regarding health issues are affected by the way in which the public obtain their knowledge, particularly whether people become interested independently, or through their social networks. This is often investigated through localized ethnography or surveys. In rapidly-evolving situations, however, there may also be a need for swift, case-specific assessment as a guide to initial strategy development.

Social versus independent interest in 'bird flu' and 'swine flu'.

The explosion of interest in H1N1, more popularly called 'swine flu', across the world, from late April to early May 2009, exemplified how information transmission in modern online society can affect the spread of the disease itself. A simple but effective model based on cultural evolutionary theory can characterise in such data the effective degree of social transmission versus independent decision. In a novel approach that applies this model to Google Trends search data, we find significant differences in social transmission of the exact phrase 'swine flu' in 2009, compared with 'bird flu' in 2005.