Biomedical subjects

Nigel Snoad

Publications and source records attributed to Nigel Snoad.

3 recordsLinked to original sources

PubMed2002

Quasispecies evolution on a fitness landscape with a fluctuating peak.

A quasispecies evolving on a fitness landscape with a single peak of fluctuating height is studied. In the approximation that back mutations can be ignored, the rate equations can be solved analytically. It is shown that the error threshold on this class of dynamic landscapes is defined by the time average of the selection pressure. In the case of a periodically fluctuating fitness peak, we also study the phase shift and response amplitude of the previously documented low-pass filter effect. The special case of a small harmonic fluctuation is treated analytically.

Biological Evolution↗

PubMed2002

Optimal mutation rates in dynamic environments.

In this paper, we study the evolution of the mutation rate for simple organisms in dynamic environments. A model based on explicit population dynamics at the gene sequence level, with multiple fitness coding loci tracking a moving fitness peak in a random fitness background, is developed and an analytical expression for the optimal mutation rate is derived. The optimal mutation rate per genome is approximately independent of genome length, something that has been observed in nature. Furthermore, the optimal mutation rate is a function of the absolute, not relative, replication rate of the superior gene sequences. Simulations confirm the theoretical predictions.

Computer Simulation↗

PubMedDate not supplied

Panel 2.18: logistics, information technology (IT), and telecommunications in crisis management.

This is a summary of the presentations and discussion of Panel 2.18, Logistics, Information Technology, and Telecommunications in Crisis Management of the Conference, Health Aspects of the Tsunami Disaster in Asia, convened by the World Health Organization (WHO) in Phuket, Thailand, 04-06 May 2005. The topics discussed included issues related to logistics, information technology (IT), and crisis communication pertaining to the responses to the damage created by the Tsunami. It is presented in the following major sections: (1) issues; (2) lessons learned; (3) what was done well; (4) what could have been done better; and (5) conclusions and recommendations. Each major section is presented in four sub-sections: (1) needs assessments; (2) coordination; (3) filling the gaps; and (4) capacity building.

Disasters↗