We take a logical approach to threshold models, used to study the diffusion of opinions, new technologies, infections, or behaviors in social networks. Threshold models consist of a network graph of agents connected by a social relationship and a threshold value which regulates the diffusion process. Agents adopt a new behavior/product/opinion when the proportion of their neighbors who have alr...

Human African trypanosomiasis or sleeping sickness is one of the most important but equally most neglected tropical infections. It is caused by a protozoan, Trypanosoma brucei, which is transmitted to humans through the bite of a tsetse fly (Glossina spp). Patchy distribution of the various vector species confines the disease to some 200 microfoci in sub-Saharan Africa (fig 1). The disease had ...

Research in diagnostic radiology often aims to establish the safety and the accuracy of a new procedure or to compare it with other procedures. Frequently, the diagnostic performance of a test can be summarized by proportions such as accuracy, sensitivity, and specificity. Safety may be reflected by the proportion of patients experiencing unpleasant or adverse effects. The confidence interval i...