Redbridge College inspection report

Inspection Week: 23 to 27 April 200

Double Hurwitz numbers via the infinite wedge

We derive an algorithm to produce explicit formulas for certain generating functions of double Hurwitz numbers. These formulas generalize a formula of Goulden, Jackson and Vakil for one part double Hurwitz numbers. Immediate consequences include a new proof that double Hurwitz numbers are piecewise polynomial, an understanding of the chamber structure and wall crossing for these polynomials, and a proof of the Goulden, Jackson and Vakil's Strong Piecewise Polynomiality conjecture. The method is a straightforward application of Okounkov's expression for double Hurwitz numbers in terms of operators on the infinite wedge. We begin with a introduction to the infinite wedge tailored to our use.Comment: 25 pages, 2 figures. Comments welcom

Extension of Nakagawa & Schielzeth's R2GLMM to random slopes models

1.Nakagawa & Schielzeth extended the widely used goodness-of-fit statistic R2 to apply to generalized linear mixed models (GLMMs). However, their R2GLMM method is restricted to models with the simplest random effects structure, known as random intercepts models. It is not applicable to another common random effects structure, random slopes models.<p></p> 2.I show that R2GLMM can be extended to random slopes models using a simple formula that is straightforward to implement in statistical software. This extension substantially widens the potential application of R2GLMM.<p></p&gt

Two generic transfers and a synonymy for some North American Elateridae (Coleoptera)

During various studies, three instances of necessary taxonomic change were found. These changes are provided here to clarify the taxonomy of these taxa for those studies

A Continuous State Space Approach to “Convergence by Parts”

Using a continuous state space approach, this note extends Feyrer's [2003] study of the proximate determinants of the shape of the long-run distribution of income per capita. Contrary to Feyrer's finding of the primacy of TFP, the results here imply that traps in both TFP growth and capital accumulation may matter.