D is an endemic mosquitotransmitted arboviral disease with an estimated 3.97 bil l ion people at risk in 128 tropical and subtropical countries around World.1 Infection by any one of the four serotypes of dengue virus (DENV-1 to DENV-4) could cause multiple spectra of disease including dengue fever, dengue shock syndrome ( D S S ) a n d d e n g u e h a e m o r r h a g i c fever (DHF). In 2008, ...

In resurgence, an operant behavior that has undergone extinction can return ("resurge") when a second operant that has replaced it itself undergoes extinction. The phenomenon may provide insight into relapse that may occur after incentive or contingency management therapies in humans. Three experiments with rats examined the impact of several variables on the strength of the resurgence effect. ...

Resurgence has commonly been viewed as the recovery of an extinguished instrumental behavior that occurs when an alternative behavior that has replaced it is also extinguished. Three experiments with rat subjects examined the effects on resurgence of the temporal distribution of reinforcement for the alternative behavior that is presented while the first response is being eliminated. Experiment...

Four experiments examined "resurgence" of an instrumental behavior after extinction. All experiments involved three phases in which rats were (1) trained to press one lever for food reward, (2) trained to press a second lever while the first leverpress was extinguished, and (3) tested under conditions in which neither leverpress was rewarded. In each experiment, the first leverpress recovered (...

Although the resurgence of pertussis in nations with long-standing vaccination programs has raised serious concerns about the effectiveness of current immunization policy, the epidemiology of resurgence remains poorly understood. We analyzed pertussis notifications in US states obtained from the National Notifiable Disease Surveillance System from 1951 to 2010 to explore the timing, spatial pat...