Speaker:

Guy Amichay, Research Associate, Engineering Sciences & Applied Mathematics, McCormick School of Engineering, Northwestern University

Title:

Biological Coupled Oscillators in the Real World

Abstract:

The study of collective synchronous behavior has primarily focused on the analysis of abstract and greatly simplified mathematical models. Many applications of these models to living systems have been proposed, but incorporation of real-world data is unfortunately rare. I will present new data and analysis regarding synchronization phenomena observed in one species of firefly from southeast Asia. Due to its relative immobility during synchronous flashing displays, this species offers a unique opportunity for reliable tracking and direct application of candidate models. We are using stereo videography to document the three-dimensional behavior of multiple swarms over multiple nights and years. Our results show that swarms exhibit “meta oscillations” characterized by order parameters that rise and fall on an intermediate time scale. This is consistent with models suggesting a “breathing” chimera state—a unique type of spatiotemporal organization that has been the subject of extensive theoretical study, but which has rarely been observed in nature. In addition, I will show preliminary data from experiments where we perturbed fireflies directly in the field with arrays of LEDs mimicking other conspecifics. On a more applied note: firefly populations (as well as many other insects) are in decline. In collaboration with Tanthai Prasertkul (Mahidol University, Thailand) we conducted a year-long population monitoring survey using our tracking software. We see a peak in abundance around June, and suggest possible weather / environmental factors that may be at play (and thus can inform us about ways of mitigating the potential collapse of the population). Finally, I will present new directions that we are now taking with recordings of groups of fiddler crabs that wave their claws in sync, and will discuss how these two distinct systems are actually comparable.

Speaker Bio:

Guy Amichay is a Research Associate at Northwestern in the Engineering Sciences & Applied Mathematics (ESAM) department, Northwestern Institute on Complex Systems (NICO) and National Institute for Theory and Mathematics in Biology (NITMB) working with Professor Daniel Abrams. He is mostly interested in self-organization—how systems manage to become ordered with no obvious leader or conductor. His current work is on synchronization (coupled oscillators), focusing on different systems such as firefly swarms flashing in unison or groups of crabs waving their claws in sync. Other than that he is also working on science of science (on the formation of collaborations) and association football (soccer) collective movement analysis. Prior to joining Northwestern, he completed his PhD at the University of Konstanz / Max Planck Institute of Animal Behavior, Germany.

Location:

In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/96400875824
Passcode: NICO24

About the Speaker Series:

Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, data science and network science. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.

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