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I work primarily on issues in spatial ecology, community assembly, and population viability, all under a conservation biological umbrella. Details can be found on my Website at http://sites.google.com/site/bricesemmens/

I am an applied population biologist. I work mainly on methods for population viability analysis and on analysis of multivariate autoregressive state-space models in ecological applications. Main projects:

• LAMBDA: MAR-1 analysis of community data vis-a-vis Ives et al 2003. (developers Steve Viscido and Eli Holmes)
  
• Kalman-EM: Estimation of constrained and unconstrained multivariate autoregressive state-space models via a Kalman filter and smoother plus EM algorithm. (developers Eli Holmes and Eric Ward)
  
• MARSS: An R package that replaces Kalman-EM.  Fully documented with help files and has a manual.  Download from CRAN or directly from your R GUI using "Install packages" (MARSS will show up on the CRAN list of available packages).  Version 2.0 (in early 2011) will provide Bayesian and data-cloning methods. (developed by Eli Holmes, Eric Ward, and Kellie Wills)
• DARTER: Diffusion Approximation Tools for Extinction Risk Estimation.  An Excel program that computes a Bayesian posterior for some PVA metrics using a Kalman filter + SIR search (developed by Brice Semmens and Eli Holmes)
• Data-cloning II: Data-cloning (vis-a-vis Lele et al., 2007, Ecology Letters) for ML estimation for MARSS models.  Uses OpenBugs (developed by Eric Ward). Simpler code for univariate case is here: Data-cloning I.
  

My papers can be found on my website: http://faculty.washington.edu/eeholmes