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Physical Sciences and Mathematics Commons™
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University of Nebraska - Lincoln
Department of Mathematics: Dissertations, Theses, and Student Research
- Keyword
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- Integral projection models (2)
- Population dynamics (2)
- Animal movement (1)
- Annuals (Plants)--Growth (1)
- Bioinformatic game theory (1)
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- Brownian motion (1)
- Compact operators (1)
- Disturbance Specialists (1)
- Ecology--Mathematical models (1)
- Essential spectrum (1)
- Global Asymptotic Stability (1)
- Herbaceous plants (1)
- Herbivore movement (1)
- Integral Projection Models (1)
- Life history theory (1)
- Mathematical Modeling (1)
- Matrix models (1)
- Measures of noncompactness (1)
- Neighborhood effect (1)
- Optimal control theory (1)
- Optimal foraging (1)
- Optimal growth (1)
- Optimal resource allocation (1)
- Perron-Frobenius Theorem (1)
- Plant growth (1)
- Population Dynamics (1)
- Population models (1)
- Positive operators (1)
- Protein clustering (1)
- Protein similarity network (1)
Articles 1 - 10 of 10
Full-Text Articles in Physical Sciences and Mathematics
Game-Theoretic Approaches To Optimal Resource Allocation And Defense Strategies In Herbaceous Plants, Molly R. Creagar
Game-Theoretic Approaches To Optimal Resource Allocation And Defense Strategies In Herbaceous Plants, Molly R. Creagar
Department of Mathematics: Dissertations, Theses, and Student Research
Empirical evidence suggests that the attractiveness of a plant to herbivores can be affected by the investment in defense by neighboring plants, as well as investment in defense by the focal plant. Thus, allocation to defense may not only be influenced by the frequency and intensity of herbivory but also by defense strategies employed by other plants in the environment. We incorporate a neighborhood defense effect by applying spatial evolutionary game theory to optimal resource allocation in plants where cooperators are plants investing in defense and defectors are plants that do not. We use a stochastic dynamic programming model, along …
Spectral Properties Of A Non-Compact Operator In Ecology, Matthew Reichenbach
Spectral Properties Of A Non-Compact Operator In Ecology, Matthew Reichenbach
Department of Mathematics: Dissertations, Theses, and Student Research
Ecologists have used integral projection models (IPMs) to study fish and other animals which continue to grow throughout their lives. Such animals cannot shrink, since they have bony skeletons; a mathematical consequence of this is that the kernel of the integral projection operator T is unbounded, and the operator is not compact. A priori, it is unclear whether these IPMs have an asymptotic growth rate λ, or a stable-stage distribution ψ. In the case of a compact operator, these quantities are its spectral radius and the associated eigenvector, respectively. Under biologically reasonable assumptions, we prove that the non-compact operators in …
Optimal Allocation Of Two Resources In Annual Plants, David Mcmorris
Optimal Allocation Of Two Resources In Annual Plants, David Mcmorris
Department of Mathematics: Dissertations, Theses, and Student Research
The fitness of an annual plant can be thought of as how much fruit is produced by the end of its growing season. Under the assumption that annual plants grow to maximize fitness, we can use techniques from optimal control theory to understand this process. We introduce two models for resource allocation in annual plants which extend classical work by Iwasa and Roughgarden to a case where both carbohydrates and mineral nutrients are allocated to shoots, roots, and fruits in annual plants. In each case, we use optimal control theory to determine the optimal resource allocation strategy for the plant …
Individual Based Model To Simulate The Evolution Of Insecticide Resistance, William B. Jamieson
Individual Based Model To Simulate The Evolution Of Insecticide Resistance, William B. Jamieson
Department of Mathematics: Dissertations, Theses, and Student Research
Insecticides play a critical role in agricultural productivity. However, insecticides impose selective pressures on insect populations, so the Darwinian principles of natural selection predict that resistance to the insecticide is likely to form in the insect populations. Insecticide resistance, in turn, severely reduces the utility of the insecticides being used. Thus there is a strong economic incentive to reduce the rate of resistance evolution. Moreover, resistance evolution represents an example of evolution under novel selective pressures, so its study contributes to the fundamental understanding of evolutionary theory.
Insecticide resistance often represents a complex interplay of multiple fitness trade-offs for individual …
Analysis Of Neuronal Sequences Using Pairwise Biases, Zachary Roth
Analysis Of Neuronal Sequences Using Pairwise Biases, Zachary Roth
Department of Mathematics: Dissertations, Theses, and Student Research
Sequences of neuronal activation have long been implicated in a variety of brain functions. In particular, these sequences have been tied to memory formation and spatial navigation in the hippocampus, a region of mammalian brains. Traditionally, neuronal sequences have been interpreted as noisy manifestations of neuronal templates (i.e., orderings), ignoring much richer structure contained in the sequences. This paper introduces a new tool for understanding neuronal sequences: the bias matrix. The bias matrix captures the probabilistic tendency of each neuron to fire before or after each other neuron. Despite considering only pairs of neurons, the bias matrix captures the best …
Bioinformatic Game Theory And Its Application To Cluster Multi-Domain Proteins, Brittney Keel
Bioinformatic Game Theory And Its Application To Cluster Multi-Domain Proteins, Brittney Keel
Department of Mathematics: Dissertations, Theses, and Student Research
The exact evolutionary history of any set of biological sequences is unknown, and all phylogenetic reconstructions are approximations. The problem becomes harder when one must consider a mix of vertical and lateral phylogenetic signals. In this dissertation we propose a game-theoretic approach to clustering biological sequences and analyzing their evolutionary histories. In this context we use the term evolution as a broad descriptor for the entire set of mechanisms driving the inherited characteristics of a population. The key assumption in our development is that evolution tries to accommodate the competing forces of selection, of which the conservation force seeks to …
Random Search Models Of Foraging Behavior: Theory, Simulation, And Observation., Ben C. Nolting
Random Search Models Of Foraging Behavior: Theory, Simulation, And Observation., Ben C. Nolting
Department of Mathematics: Dissertations, Theses, and Student Research
Many organisms, from bacteria to primates, use stochastic movement patterns to find food. These movement patterns, known as search strategies, have recently be- come a focus of ecologists interested in identifying universal properties of optimal foraging behavior. In this dissertation, I describe three contributions to this field. First, I propose a way to extend Charnov's Marginal Value Theorem to the spatially explicit framework of stochastic search strategies. Next, I describe simulations that compare the efficiencies of sensory and memory-based composite search strategies, which involve switching between different behavioral modes. Finally, I explain a new behavioral analysis protocol for identifying the …
Modeling And Mathematical Analysis Of Plant Models In Ecology, Eric A. Eager
Modeling And Mathematical Analysis Of Plant Models In Ecology, Eric A. Eager
Department of Mathematics: Dissertations, Theses, and Student Research
Population dynamics tries to explain in a simple mechanistic way the variations of the size and structure of biological populations. In this dissertation we use mathematical modeling and analysis to study the various aspects of the dynamics of plant populations and their seed banks.
In Chapter 2 we investigate the impact of structural model uncertainty by considering different nonlinear recruitment functions in an integral projection model for Cirsium canescens. We show that, while having identical equilibrium populations, these two models can elicit drastically different transient dynamics. We then derive a formula for the sensitivity of the equilibrium population to …
Mathematical Modeling Of Optimal Seasonal Reproductive Strategies And A Comparison Of Long-Term Viabilities Of Annuals And Perennials, Anthony Delegge
Mathematical Modeling Of Optimal Seasonal Reproductive Strategies And A Comparison Of Long-Term Viabilities Of Annuals And Perennials, Anthony Delegge
Department of Mathematics: Dissertations, Theses, and Student Research
In 1954, Lamont Cole posed a question which has motivated much ecological work in the past 50 years: When is the life history strategy of semelparity (organisms reproduce once, then die) favored, via evolution, over iteroparity (organisms may reproduce multiple times in their lifetime)? Although common sense should dictate that iteroparity would always be favored, we can observe that this is not always the case, since annual plants are not only prevalent, but can dominate an area. Also, certain plant species may be perennial in one region, but annual in another. Thus, in these areas, certain characteristics must be present …
Modeling And Analysis Of Biological Populations, Joan Lubben
Modeling And Analysis Of Biological Populations, Joan Lubben
Department of Mathematics: Dissertations, Theses, and Student Research
Asymptotic and transient dynamics are both important when considering the future population trajectory of a species. Asymptotic dynamics are often used to determine whether the long-term trend results in a stable, declining or increasing population and even provide possible directions for management actions. Transient dynamics are important for estimating invasion speed of non-indigenous species, population establishment after releasing biocontrol agents, or population management after a disturbance like fire. We briefly describe here the results in this thesis.
(1) We consider asymptotic dynamics using discrete time linear population models of the form n(t + 1) = An(t) where …