Sample A: Cover Page of Thesis, Project, or Dissertation Proposal

malaria and leishmaniasis, and vectors such as Anopheles gambiae (Peterson and Shaw 2003,
Levine et al. 2004, Peterson et al. 2004, Peterson et al. 2005).
MaxEnt Program for Ecological Niche Modeling
This study utilizes a maximum entropy approach to develop an ecological niche
model of the distribution of RVF competent vectors across the state of Virginia. 6 MaxEnt
version 3.2.1 (Phillips et al. 2004, Phillips et al. 2006), the application used here, is easy to
use, batchable, and has produced useful predictions of species distributions, likelihood of
establishment, and alterations of ranges caused by climate change (Phillips et al. 2004,
Hernandez et al. 2006). Having presence-only data for this study, MaxEnt was a reasonable
method to select because it does not require an explicit quantification of absence to formulate
a predicted distribution model (Phillips et al. 2004). In addition, Elith et al. 2006 found that
MaxEnt was one of the strongest performers in a large model comparison study. Also
noteworthy, Hernandez et al. (2006) evaluated four species distribution modeling methods
and concluded that MaxEnt was the most capable in producing useful results with stable
prediction accuracy even when sample sizes were small.
MaxEnt produces predictions from incomplete information by estimating the most
uniform distribution (maximum entropy) of occurrence points across the study area. MaxEnt
is designed to estimate a target probability distribution by finding the probability distribution
6 Initially co-kriging, a common geostatistical technique that provides a means of using predictor variables
to interpolate values for unrecorded locations and calculate a measure of variance around estimated values,
was considered for these analyses. However, after an initial attempt to interpolate mosquito abundance and
distribution using environmental-climatic variables it was evident that co-kriging could not adequately
estimate mosquito values because the surveillance data was clustered in three region (Northern Virginia,
Richmond-Petersburg, and Hampton Roads).
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