Disease Ecology
Within-Host Dynamics of Cereal Yellow Dwarf Virus (CYDV)
Within-Host Dynamics of Cereal Yellow Dwarf Virus (CYDV)
Understanding how diseases affect growth and the nutritional value of plants is a significant challenge for supporting a growing human population and satisfying its demand for sustainable food and fuel resources. My collaborators and I are validating mathematical models of within-host dynamics of CYDV, an aphid-vectored disease of many grains and grasses. I’m working with Dr. Yang Kuang in mathematics, Amy Kendig, Dr. Elizabeth Borer and Dr. Eric Seabloom from evolutionary biology at the University of Minnesota to model and investigate different nutrient treatments of nitrogen (N) and phosphorus (P) on virion dynamics. We are motivated by laboratory experiments where a common oat plant was inoculated with CYDV under 4 nutrient regiments: control, P addition, N addition and both P and N addition.
Understanding how diseases affect growth and the nutritional value of plants is a significant challenge for supporting a growing human population and satisfying its demand for sustainable food and fuel resources. My collaborators and I are validating mathematical models of within-host dynamics of CYDV, an aphid-vectored disease of many grains and grasses. I’m working with Dr. Yang Kuang in mathematics, Amy Kendig, Dr. Elizabeth Borer and Dr. Eric Seabloom from evolutionary biology at the University of Minnesota to model and investigate different nutrient treatments of nitrogen (N) and phosphorus (P) on virion dynamics. We are motivated by laboratory experiments where a common oat plant was inoculated with CYDV under 4 nutrient regiments: control, P addition, N addition and both P and N addition.
Our recent work has shown that nutrients mediated virulence through changes in host growth when the virulence was either caused by pathogen presence or resource-use. However, changes in pathogen concentration due to nutrient availability only affected virulence when the pathogen was competing with the host for resources. While we have not observed strong effects of coinfection and nutrient availability on virulence in the empirical system, the mathematical model identified situations in which environmental nutrient supply rates are likely to influence the impact of infectious diseases.
Our recent work has shown that nutrients mediated virulence through changes in host growth when the virulence was either caused by pathogen presence or resource-use. However, changes in pathogen concentration due to nutrient availability only affected virulence when the pathogen was competing with the host for resources. While we have not observed strong effects of coinfection and nutrient availability on virulence in the empirical system, the mathematical model identified situations in which environmental nutrient supply rates are likely to influence the impact of infectious diseases.
Relevant papers:
Relevant papers:
T. Phan, B. Pell, A. E. Kendig, E. T. Borer, Y. Kuang. Rich dynamics of a simple delay host-pathogen model of cell-to-cell infection for plant virus. Discrete & Continuous Dynamical Systems-B, 2020.
T. Phan, B. Pell, A. E. Kendig, E. T. Borer, Y. Kuang. Rich dynamics of a simple delay host-pathogen model of cell-to-cell infection for plant virus. Discrete & Continuous Dynamical Systems-B, 2020.
B. Pell, A. E. Kendig, E. T. Borer, Y. Kuang. Modeling nutrient and disease dynamics in a plant-pathogen system. Math Biosci Eng. 2018;16(1):234‐264.
B. Pell, A. E. Kendig, E. T. Borer, Y. Kuang. Modeling nutrient and disease dynamics in a plant-pathogen system. Math Biosci Eng. 2018;16(1):234‐264.
Temperature Performance Curves and Metabolic Theory of Ecology
Temperature Performance Curves and Metabolic Theory of Ecology
I work with Thomas Raffel and his laboratory at Oakland University to understand how temperature influences parasite infections in frogs.
I work with Thomas Raffel and his laboratory at Oakland University to understand how temperature influences parasite infections in frogs.
The metabolic theory of ecology is a conceptual framework in ecology that aims to explain various ecological patterns and processes based on the fundamental principles of energy and metabolism. It proposes that the rates of biological processes, such as growth, reproduction, and mortality, are strongly influenced by an organism's metabolic rate, which is primarily determined by temperature. Here's a summary of the metabolic theory of ecology and how thermal performance curves can be used to understand outcomes related to host and parasite infections:
The metabolic theory of ecology is a conceptual framework in ecology that aims to explain various ecological patterns and processes based on the fundamental principles of energy and metabolism. It proposes that the rates of biological processes, such as growth, reproduction, and mortality, are strongly influenced by an organism's metabolic rate, which is primarily determined by temperature. Here's a summary of the metabolic theory of ecology and how thermal performance curves can be used to understand outcomes related to host and parasite infections:
Metabolic Theory of Ecology (MTE):
Metabolic Theory of Ecology (MTE):
(1) MTE posits that an organism's metabolic rate scales with its body size, with smaller organisms having higher mass-specific metabolic rates (metabolism per unit of body mass) compared to larger organisms.
(1) MTE posits that an organism's metabolic rate scales with its body size, with smaller organisms having higher mass-specific metabolic rates (metabolism per unit of body mass) compared to larger organisms.
(2) Temperature plays a crucial role in shaping an organism's metabolic rate. As temperature increases, metabolic rates also rise, which has significant implications for an organism's physiology, behavior, and ecological interactions.
(2) Temperature plays a crucial role in shaping an organism's metabolic rate. As temperature increases, metabolic rates also rise, which has significant implications for an organism's physiology, behavior, and ecological interactions.
(3) MTE provides a unifying framework for understanding a wide range of ecological phenomena, including species distributions, population dynamics, and ecosystem processes.
(3) MTE provides a unifying framework for understanding a wide range of ecological phenomena, including species distributions, population dynamics, and ecosystem processes.
Thermal Performance Curves (TPCs):
Thermal Performance Curves (TPCs):
(1) Thermal performance curves are graphical representations that depict how an organism's performance (e.g., growth rate, reproductive output, or survival) changes with varying temperatures.
(1) Thermal performance curves are graphical representations that depict how an organism's performance (e.g., growth rate, reproductive output, or survival) changes with varying temperatures.
(2) TPCs typically have a concave-down curve, with an optimal temperature range where performance is highest, and performance declining as temperatures deviate from this range.
(2) TPCs typically have a concave-down curve, with an optimal temperature range where performance is highest, and performance declining as temperatures deviate from this range.
(3) The shape and characteristics of TPCs are species-specific and can be influenced by an organism's evolutionary history, habitat, and physiological adaptations.
(3) The shape and characteristics of TPCs are species-specific and can be influenced by an organism's evolutionary history, habitat, and physiological adaptations.
Understanding Host-Parasite Interactions Using TPCs:
Understanding Host-Parasite Interactions Using TPCs:
(1) Thermal performance curves can be applied to understand outcomes in host-parasite interactions, where both hosts and parasites have their own TPCs.
(1) Thermal performance curves can be applied to understand outcomes in host-parasite interactions, where both hosts and parasites have their own TPCs.
(2) Hosts and parasites may have different optimal temperature ranges, and their performance can be affected differently by temperature changes.
(2) Hosts and parasites may have different optimal temperature ranges, and their performance can be affected differently by temperature changes.
(3) When host and parasite TPCs are mismatched, it can lead to variable outcomes in terms of infection dynamics and disease prevalence.
(3) When host and parasite TPCs are mismatched, it can lead to variable outcomes in terms of infection dynamics and disease prevalence.
(4) Temperature can influence not only host and parasite performance but also the transmission rates and virulence of parasites, ultimately affecting the dynamics of host-parasite interactions.
(4) Temperature can influence not only host and parasite performance but also the transmission rates and virulence of parasites, ultimately affecting the dynamics of host-parasite interactions.
In summary, the metabolic theory of ecology provides a foundation for understanding the influence of temperature on metabolic rates and ecological processes. Thermal performance curves serve as valuable tools to assess how temperature affects the performance of organisms, including hosts and parasites. By examining the interactions between the TPCs of hosts and parasites, researchers can gain insights into the outcomes and dynamics of host-parasite relationships in response to changing environmental temperatures.
In summary, the metabolic theory of ecology provides a foundation for understanding the influence of temperature on metabolic rates and ecological processes. Thermal performance curves serve as valuable tools to assess how temperature affects the performance of organisms, including hosts and parasites. By examining the interactions between the TPCs of hosts and parasites, researchers can gain insights into the outcomes and dynamics of host-parasite relationships in response to changing environmental temperatures.