Research in the Brooks Lab

Ecological Networks and Disease Transmission
Within any population there exist differences between individuals in their dispersal ability, resistance to infection, and even the degree to which they interact with other individuals in the population. The effect is that some individuals have a disproportionately large influence on processes like disease transmission than will others in the population. We can represent this heterogeneity in theoretical models using a discrete mathematical structure called a graph (sometimes called a network model). Here, hosts (or habitat patches) are represented by vertices while potential interaction between any pair of vertices (through transmission or dispersal) is represented by an edge. Our lab is interested in spatially-explicit network models and their potential for 'scaling-up' local interactions to predict metapopulation dynamics.

Publications

Brooks, C.P., J. Antonovics and T.H. Keitt. in press. Metapopulation dynamics and persistence are explained by temporal heterogeneity in spatial network structure. American Naturalist (see press release here)

Brooks, C.P. 2006. Quantifying population substructure: Extending the graph-theoretic approach. Ecology 87(4): 864-872.

Brooks, C.P. 2003. A scalar analysis of connectivity. Oikos. 102(2): 433-439.

Species Invasions: Conservation Medicine & Invasive Species

Just as there are differences among individuals within a population in their ability to transmit disease, there are also differences among species in a community in their competence as hosts. As a result, we might expect that changes in the number of species or in the actual composition of host communities might have consequences to the dynamics of infection for generalist (or multi-host) pathogens. Theoretical work in the lab generally focuses on the use of differential equationsand/or graph-based (network) models of interaction. This theoretical work is used to generate testable hypotheses that direct our empirical projects. Empirical work in the Brooks Lab is currently focused on two projects: the first involves the South American Cactus Moth, Cactoblastis cactorum. In collaboration with the Ervin, Welch, and Wallace labs we are exploring the role of community structure and genetic diversity on the spread of the moth both in its native range and in North America. Our second empirical focus in on the role of fish diversity in the population dynamics of Unionid mussels (whose juveniles are obligate parasites on fish) in northern Mississippi.

Publications

Brooks, C.P. and J.D. Achter. in prep. Modeling public health risk along gradients in host diversity. Ecology Letters.

Webb, C.T.*, C.P. Brooks*, K.L. Gage and M.F. Antolin. 2006. Classic flea-borne transmission does not drive plague epizootics in prairie dogs. Proc. Nat. Acad. USA 103(16): 6236-6241.
* contributed equally

The Dynamics of Leprosy in Wild Armadillo Populations
There are few diseases that evoke the kind or visceral responses from people that Leprosy does. Just as is the case with plague, leprosy is among the handful of diseases that has influenced the history of human populations in a tangible way. Within the last 50 years researchers studying the biology of Mycobacterium leprae, the causative agent for leprosy, noted that armadillos were an excellent laboratory model for the disease because of their exceptionally low metabolic rates. As it turns out, armadillos are excellent hosts for the pathogen, having harbored the pathogen in an apparently endemic state in wild populations for many years prior to their use in the lab. While we know something about the geographic distribution of M. leprae infections in Louisiana and Texas, we know very little about its distribution elsewhere. Likewise, we do not know the primary mode of transmission (and that extends to human-human and human-armadillo contacts as well). Our lab is currently working to model the large-scale ecological factors associated with the foci of leprosy in the United States and to explore the potential modes of transmission for M. leprae in armadillo populations.

Publications

Other Publications

Brooks, C.P., B. Barnett, C. Holmes, K. Kramer and T.H. Keitt. in prep. Elucidating household-level drivers of deforestation near Ranomafana National Parc, Madagascar. Conservation Letters.

Brooks, C.P. and C.V. Hawkes. in prep. Patterns of infection in a grassland community along a gradient in precipitation.



			Ecological Networks and Disease Transmission Within any population there exist differences between individuals in their dispersal ability, resistance to infection, and even the degree to which they interact with other individuals in the population. The effect is that some individuals have a disproportionately large influence on processes like disease transmission than will others in the population. We can represent this heterogeneity in theoretical models using a discrete mathematical structure called a graph (sometimes called a network model). Here, hosts (or habitat patches) are represented by vertices while potential interaction between any pair of vertices (through transmission or dispersal) is represented by an edge. Our lab is interested in spatially-explicit network models and their potential for 'scaling-up' local interactions to predict metapopulation dynamics. Publications Brooks, C.P., J. Antonovics and T.H. Keitt. in press. Metapopulation dynamics and persistence are explained by temporal heterogeneity in spatial network structure. American Naturalist (see press release here) Brooks, C.P. 2006. Quantifying population substructure: Extending the graph-theoretic approach. Ecology 87(4): 864-872. Brooks, C.P. 2003. A scalar analysis of connectivity. Oikos. 102(2): 433-439.

			Species Invasions: Conservation Medicine & Invasive Species Just as there are differences among individuals within a population in their ability to transmit disease, there are also differences among species in a community in their competence as hosts. As a result, we might expect that changes in the number of species or in the actual composition of host communities might have consequences to the dynamics of infection for generalist (or multi-host) pathogens. Theoretical work in the lab generally focuses on the use of differential equationsand/or graph-based (network) models of interaction. This theoretical work is used to generate testable hypotheses that direct our empirical projects. Empirical work in the Brooks Lab is currently focused on two projects: the first involves the South American Cactus Moth, Cactoblastis cactorum. In collaboration with the Ervin, Welch, and Wallace labs we are exploring the role of community structure and genetic diversity on the spread of the moth both in its native range and in North America. Our second empirical focus in on the role of fish diversity in the population dynamics of Unionid mussels (whose juveniles are obligate parasites on fish) in northern Mississippi. Publications Brooks, C.P. and J.D. Achter. in prep. Modeling public health risk along gradients in host diversity. Ecology Letters. Webb, C.T., C.P. Brooks, K.L. Gage and M.F. Antolin. 2006. Classic flea-borne transmission does not drive plague epizootics in prairie dogs. Proc. Nat. Acad. USA 103(16): 6236-6241. * contributed equally

			The Dynamics of Leprosy in Wild Armadillo Populations There are few diseases that evoke the kind or visceral responses from people that Leprosy does. Just as is the case with plague, leprosy is among the handful of diseases that has influenced the history of human populations in a tangible way. Within the last 50 years researchers studying the biology of Mycobacterium leprae, the causative agent for leprosy, noted that armadillos were an excellent laboratory model for the disease because of their exceptionally low metabolic rates. As it turns out, armadillos are excellent hosts for the pathogen, having harbored the pathogen in an apparently endemic state in wild populations for many years prior to their use in the lab. While we know something about the geographic distribution of M. leprae infections in Louisiana and Texas, we know very little about its distribution elsewhere. Likewise, we do not know the primary mode of transmission (and that extends to human-human and human-armadillo contacts as well). Our lab is currently working to model the large-scale ecological factors associated with the foci of leprosy in the United States and to explore the potential modes of transmission for M. leprae in armadillo populations. Publications

			Other Publications Brooks, C.P., B. Barnett, C. Holmes, K. Kramer and T.H. Keitt. in prep. Elucidating household-level drivers of deforestation near Ranomafana National Parc, Madagascar. Conservation Letters. Brooks, C.P. and C.V. Hawkes. in prep. Patterns of infection in a grassland community along a gradient in precipitation.