Recursive estimation of possibly misspecified MA(1) models: Convergence of a general algorithm

We introduce a recursive algorithm of conveniently general form for estimating the coefficient of a moving average model of order one and obtain convergence results for both correct and misspecified MA(1) models. The algorithm encompasses Pseudolinear Regression (PLR--also referred to as AML and $RML_1$) and Recursive Maximum Likelihood ($RML_2$) without monitoring. Stimulated by the approach of Hannan (1980), our convergence results are obtained indirectly by showing that the recursive sequence can be approximated by a sequence satisfying a recursion of simpler (Robbins-Monro) form for which convergence results applicable to our situation have recently been obtained.Comment: Published at http://dx.doi.org/10.1214/074921706000000932 in the IMS Lecture Notes Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

Algorithms for Olfactory Search across Species

Localizing the sources of stimuli is essential. Most organisms cannot eat, mate, or escape without knowing where the relevant stimuli originate. For many, if not most, animals, olfaction plays an essential role in search. While microorganismal chemotaxis is relatively well understood, in larger animals the algorithms and mechanisms of olfactory search remain mysterious. In this symposium, we will present recent advances in our understanding of olfactory search in flies and rodents. Despite their different sizes and behaviors, both species must solve similar problems, including meeting the challenges of turbulent airflow, sampling the environment to optimize olfactory information, and incorporating odor information into broader navigational systems

Zea diploperennis: A Primitive Relative Offers New Traits to Improve Corn

Four years ago, a young Mexican botanist made what may someday be recognized as the botanical find of the century. Rafael Guzmán, a student at the University of Guadalajara, was searching for one of the wild relatives of corn in the mountains of southern Mexico. Guzmán was looking for Zea perennis, a perennial teosinte thought to be extinct in the wild since the early 1920\u27s. This primitive corn relative was considered more of a botanical curiosity than a boon to mankind. As a tetraploid, perennial teosinte produces sterile offspring when crossed with corn, a diploid species. Guzmán found perennial teosinte growing in a remote mountain site

Energy of the Conduction Band in Near Critical Point Fluids

The study of the evolution of the conduction band in dense gases and supercritical fluids near the critical point has been complicated by a lack of precise experimental measurements. Both photoemission from an electrode immersed in the fluid and field ionization of a molecule doped into the fluid have been used to probe solvent density effects on the energy of an excess electron as a function of fluid number density and temperature. In this perspective, we present recent experimental results that show a strong critical point effect on the minimum conduction band energy near the critical density and temperature of a fluid. We also discuss the recent development of a new theoretical model that advances our understanding of the density and temperature dependence of the conduction band minimum in near critical point fluids