Physical Sciences and Mathematics Commons^™

A Phenological Model For A Southern Population Of Mountain Pine Beetle, Catherine E. Wangen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mountain pine beetle (MPB, Dendroctonus ponderosae Hopkins) attacks living Pinus trees across a widespread area of western North America, causing significant ecological and economic damage. The ability to make accurate predictions of how MPB populations across this range will respond to temperatures, which affect MPB progress through life stages, is essential. Northern and southern populations of MPB are genetically different in response to temperature, requiring geographic-specific model parameters. There is not currently a predictive model for the southern MPB life cycle, despite concerns that those populations may be more susceptible to increased numbers of generations per year, which would …

Beetles, Fungi And Trees: A Story For The Ages? Modeling And Projecting The Multipartite Symbiosis Between The Mountain Pine Beetle, Dendroctonus Ponderosae, And Its Fungal Symbionts, Grosmannia Clavigera And Ophiostoma Montium, Audrey L. Addison

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As data collection and modeling improve, ecologists increasingly discover that interspecies dynamics greatly affect the success of individual species. Models accounting for the dynamics of multiple species are becoming more important. In this work, we explore the relationship between mountain pine beetle (MPB, Dendroctonus ponderosae Hopkins) and two mutualistic fungi, Grosmannia clavigera and Ophiostoma montium. These species are involved in a multipartite symbiosis, critical to the survival of MPB, in which each species benefits.

Extensive phenological modeling has been done to determine how temperature affects the timing of life events and cold-weather mortality of MPB. The fungi have also …

Statistical Properties And Problems In Modeling The Bolivian Foreign Exchange Market, Gover Barja

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Bolivian foreign exchange market is explained in terms of the official and parallel exchange rates. The data covers the post hyper inflationary period from 1986 to 1992. The distribution of the rate of depreciation of the official and parallel exchange rates is long tailed and strongly departs from normality due to the existence of outliers. A market interactions model of the autoregressive kind is estimated using robust regression. This procedure produces M-parameter estimates using iteratively reweighted least squares. The robust method handles well the outlier problem and at the same time it reveals the true nature of the statistical …