User:Carl Boettiger/Notebook/Stochastic Population Dynamics/2010/05/10

{| width="800"
 * style="background-color: #EEE"|[[Image:owwnotebook_icon.png|128px]] Stochastic Population Dynamics
 * style="background-color: #F2F2F2" align="center"|  |Main project page
 * style="background-color: #F2F2F2" align="center"|  |Main project page


 * colspan="2"|
 * colspan="2"|

Updates

 * 1)  Likelihood calculation for beetle model.
 * 2) Proposed model and calculations  Linear parameter change  for warning signal model.   Results  in a few test cases.
 * 3) Likelihood methods within SDE framework, an  outline of methods.  Subtle problems, good approximations, powerful approaches.

Questions

 * 1) LPA vs ELLPA model
 * 2) Defining state space in individual-based model vs stage based model, setting initial conditions?  Conclusion: Means non-Markovian system, so likelihood isn't determined in one step approach.  More lit review, see:   Ellner Ellner, Perry, Perry, Perry2, Perry3
 * 3) Calculating likelihood while accounting for non-independence of the occupancy of each stage?  Focus on one class?  Conclusions: Choose Larvae.

Parameter fitting
On likelihood based model selection vs model based estimates of process:
 * Some cases maximum likelihood estimate agrees with statistical definition -- variance definition is mle of sigma parameter for indep gaussian random numbers, the arithmetic mean is the mle for lambda in the poisson, etc. Doesn't necessarily hold true in these time-series analyses, at least for numerical fitting.  Would be better to estimate theta from the mean and search for other parameters.
 * requires more precise parameterization

Research: Themes for Weds/Thurs workshop with Bob and Brett
Why is this all important?
 * Importance of space
 * Importance of environmental variation
 * Importance of intrinsic variation <- us

A recipe for trouble
 * Age or stage structure
 * Density dependence
 * demographic stochasticity

Open Access

 * Answering a question for a colleague about whether posting on arxiv was consistent with Elsevier's policies. (It is). Many Eslevier journals including TPB provide a watermarked authors copy of post-publication pdf explicitly for posting on the author's website and sharing with colleagues.


 * Fun stats: 90% of journals allow archiving preprints, many major funders (NIH, Wellcome) and require open archives, and the FRPAA bill now before congress would require it for almost all public funding. Very few publishers maintain the Ingelfinger rule of refusing to publish things that are archived before publication. Open archives are now the norm.


 * arXiv's endorsement system seems to be a source of confusion sometimes. Our TPB paper on arXiv.

Open Education

 * This is how we dream a fantastic piece on the changing media of writing.  part 2.  From Richard Miller, at Rutgers.
 * AcademiX an exciting conference on the open future of learning.


 * }