Open Access. Powered by Scholars. Published by Universities.®

Medicine and Health Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Medicine and Health Sciences

Effects Of Temperature On Emergence And Seasonality Of West Nile Virus In California, David M. Hartley, Christopher M. Barker, Arnaud Le Menach, Tianchan Niu, Holly Gaff, William K. Reisen May 2012

Effects Of Temperature On Emergence And Seasonality Of West Nile Virus In California, David M. Hartley, Christopher M. Barker, Arnaud Le Menach, Tianchan Niu, Holly Gaff, William K. Reisen

Biological Sciences Faculty Publications

Temperature has played a critical role in the spatiotemporal dynamics of West Nile virus transmission throughout California from its introduction in 2003 through establishment by 2009. We compared two novel mechanistic measures of transmission risk, the temperature-dependent ratio of virus extrinsic incubation period to the mosquito gonotrophic period (BT), and the fundamental reproductive ratio (R0) based on a mathematical model, to analyze spatiotemporal patterns of receptivity to viral amplification. Maps of BT and R0 were created at 20-km scale and compared throughout California to seroconversions in sentinel chicken flocks at half-month intervals. Overall, estimates of BT and …


Cyanobacteria Dominance In The Oligohaline Waters Of Back Bay, Virginia, Harold G. Marshall Jan 2012

Cyanobacteria Dominance In The Oligohaline Waters Of Back Bay, Virginia, Harold G. Marshall

Biological Sciences Faculty Publications

Back Bay and its flora have historically been influenced by the interaction of freshwater flow in combination with frequent intrusion of saline water into its basin. These events have resulted in a dynamic environmental setting influencing the abundance and composition of its phytoplankton community. Dominating these oligohaline waters is a diverse representation and high abundance of freshwater filamentous and colonial cyanobacteria. These include the nonheterocystous Planktolyngbya contorta, Planktolyngbya limnetica, and Pseudanabaena limnetica, taxa implicated as bloom producers in Bay waters with N:P molar ratios ranging from 23:1 to 74:1.


An Epidemiological Model Of Rift Valley Fever With Spatial Dynamics, Tianchan Niu, Holly D. Gaff, Yiannis E. Papelis, David M. Hartley Jan 2012

An Epidemiological Model Of Rift Valley Fever With Spatial Dynamics, Tianchan Niu, Holly D. Gaff, Yiannis E. Papelis, David M. Hartley

Biological Sciences Faculty Publications

As a category A agent in the Center for Disease Control bioterrorism list, Rift Valley fever (RVF) is considered a major threat to the United States (USA). Should the pathogen be intentionally or unintentionally introduced to the continental USA, there is tremendous potential for economic damages due to loss of livestock, trade restrictions, and subsequent food supply chain disruptions. We have incorporated the effects of space into a mathematical model of RVF in order to study the dynamics of the pathogen spread as affected by the movement of humans, livestock, and mosquitoes. The model accounts for the horizontal transmission of …