20 research outputs found
Universal time-dependent deformations of Schrodinger geometry
We investigate universal time-dependent exact deformations of Schrodinger
geometry. We present 1) scale invariant but non-conformal deformation, 2)
non-conformal but scale invariant deformation, and 3) both scale and conformal
invariant deformation. All these solutions are universal in the sense that we
could embed them in any supergravity constructions of the Schrodinger invariant
geometry. We give a field theory interpretation of our time-dependent
solutions. In particular, we argue that any time-dependent chemical potential
can be treated exactly in our gravity dual approach.Comment: 24 pages, v2: references adde
Quantifying the Emergence of Dengue in Hanoi, Vietnam: 1998–2009
Dengue is the most common vector-borne viral disease of humans, causing an estimated 50 million cases per year. The number of countries affected by dengue has increased dramatically in the last 50 years and dengue is now a major public health problem in large parts of the tropical and subtropical world. It is of considerable importance to understand the factors that determine how dengue becomes newly established in areas where the risk of dengue was previously small. Hanoi in North Vietnam is a large city where dengue appears to be emerging. We analyzed 12 years of dengue surveillance data in order to characterize the temporal and spatial epidemiology of dengue in Hanoi and to establish if dengue incidence has been increasing. After excluding the two major outbreak years of 1998 and 2009 and correcting for changes in population age structure over time, we found there was a significant annual increase in the incidence of notified dengue cases over the period 1999–2008. Dengue cases were concentrated in young adults in the highly urban central areas of Hanoi. This study indicates that dengue transmission is increasing in Hanoi and provides a platform for further studies of the underlying drivers of this emergence