Dear All,
You are most cordially invited to the ICTP Colloquium by
Prof. Mercedes Pascual, New York University
, on "Hyper-diversity and negative
frequency-dependent interactions in host-pathogen systems".
The Colloquium will take place (in presence) today Wednesday 29
May 2024 at 14:00 hrs in the Budinich Lecture Hall.
Biosketch:
Mercedes Pascual is a Professor of Biology and Environmental
Studies at New York University, and an external faculty of the
Santa Fe Institute. Dr. Pascual is a theoretical ecologist
interested in the population dynamics of infectious diseases,
their response to changing environments and their interplay with
pathogen diversity. She is also interested in the structure and
dynamics of large interaction networks in ecology and
epidemiology. Dr. Pascual received her Ph.D. degree from the joint
program of the Woods Hole Oceanographic Institution and the
Massachusetts Institute of Technology. She was awarded a U.S.
Department of Energy Alexander Hollaender Distinguished
Postdoctoral Fellowship for studies at Princeton University, and a
Centennial Fellowship in the area of Global and Complex Systems by
the James S. McDonnell Foundation for her research at the
University of Michigan. She received the Robert H. MacArthur
award from the Ecological Society of America. She is a fellow of
the American Association for the Advancement of Science and a
member of the American Academy of Arts and Sciences.
Abstract:
How important are specific ecological interactions to the
assembly of a diverse community of species? Can coexistence
reflect instead neutral assembly, simply resulting from stochastic
birth-death processes? What signatures in macroscopic diversity
patterns can help us distinguish among these two explanations?
These long-standing questions from Ecology and its interplay with
Evolution, can be similarly asked at a different level of
biological organization for strain diversity within a pathogen
population. I do so here for the hyper-diverse malaria parasite
Plasmodium falciparum in high-transmission regions. Strains
compete for hosts as these acquire specific immune memory, which
creates an advantage of the rare and a disadvantage of the common,
resulting in negative frequency-dependent selection (NFDS). I show
that networks describing patterns of limiting similarity can help
us identify the importance of this non-neutral process to
coexistence. With a more analytically tractable PDE model, I
further discuss implications of the positive feedback between
diversity and transmission/competition intensity for resilience of
the pathogen population. I end with brief mention of other
microbial populations of large diversity under NFDS, and of other
ecological systems to which similar ideas may apply.
Light
refreshments will be served on the Leonardo Building Terrace at
the end of the talk.
Looking
forward to your participation.
With best regards,
Director's Office, ICTP