Events
Past Event
WED@NICO SEMINAR: Srividya Iyer-Biswas, Purdue University "Emergent laws governing stochastic single-cell dynamics"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Srividya Iyer-Biswas, Assistant Professor, Purdue University, Department of Physics and Astronomy
Title:
Emergent laws governing stochastic single-cell dynamics
Abstract:
There has been a longstanding quest to uncover the quantitative laws governing the stochastic growth and division of individual cells. While great strides have been made in unravelling and modeling the details of the gene regulatory networks which dictate growth and division for different organisms, there is regrettable paucity of quantitative physical laws derived from the complementary “top down” perspective. Introducing the unique combination of technologies that facilitated probing these stochastic cellular dynamics with unprecedented precision, I will first summarize the "scaling laws" that govern fluctuations in growth and division of individual cells under steady-state growth conditions. Taking the minimalist perspective, I will argue for how these scaling laws reveal an elegant physical principle governing these complex biological processes: a single cellular unit of time, which scales with external conditions, governs all aspects of stochastic cell growth and division at a given condition. I will then focus on applications of the technology to probe more complex growth conditions, the corresponding generalizations of the physical principle, and the implications for the underlying biological systems design. Finally, I propose an integrative perspective of microbial growth dynamics under balanced conditions, by introducing a multi-scale theoretical framework that takes observables at both scales, single-cell and population, into account. Time permitting, I will make connections with energetic costs of cellular information processing.
Speaker Bio:
Using rapid, iterative feedback between theory and experiments, Srividya Iyer-Biswas works to discover the basic physical laws that govern the probabilistic behavior of single cells, and that transcend details of specific biological systems. Her research uses a top-down physics approach, rather than more traditional approaches that focus on the cartography of genetic networks and on molecular details.
Iyer-Biswas and her team have reported predicative scaling laws governing the stochastic growth and division of cells, and have developed a theory that reveals the emergence of a scalable, cellular unit of time. Her current work involves extending these results to thermodynamics of organismal computation, time-dependent phenomena involving cellular decision-making, and laws that dictate complex biological and social phenomena. Iyer-Biswas began her career as a theoretical physicist, then transitioned to experimental biophysics as a post-doc at Princeton University and the University of Chicago. She is currently an Assistant Professor in Purdue University's Department of Physics and Astronomy.
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems and data 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.
Time
Wednesday, October 3, 2018 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
No classes - Memorial Day - University offices are closed
University Academic Calendar
All Day
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No classes - Memorial Day - University offices are closed
Time
Monday, May 25, 2026
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University Academic Calendar
Data Science Nights - MAY 2026 - Speaker: Xudong Tang, Computer Science and NICO
Northwestern Institute on Complex Systems (NICO)
5:30 PM
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M416, Technological Institute
Details
MAY MEETING: Thursday, May 28, 2026 at 5:30pm (US Central)
LOCATION:
ESAM Conference Room, Tech M416
2145 Sheridan Road, Evanston, IL 60208
AGENDA:
5:30pm - Meet and greet with refreshments
6:00pm - Talk with Xudong Tang, PhD Student, Computer Science, NICO, and the Human-AI Collaboration Lab, Northwestern University
TALK TITLE:
Human and Machine Perception of Voice Similarity
ABSTRACT:
Modern voice cloning systems generate synthetic speech that listeners frequently cannot identify as being synthetic. But a voice can sound natural without sounding like the intended person, and what determines whether a clone is heard as a particular person is an open question. Here we report a large-scale preregistered experiment in which we collected 92,239 responses from 175 participants on their perception of pairs of real recordings, voice clones, and continuously morphed voices drawn from 100 contemporary celebrities across 20 speaker groups. We find that voice clones do not reliably preserve perceived speaker identity, reducing same-speaker judgments by 12.7 percentage points even though the clones are produced by a state-of-the-art text-to-speech model, while leaving different-speaker judgments unchanged. Using continuously morphed stimuli, we find that speakers vary substantially in how much variation their perceived identity tolerates, and that this variation is not predicted by speaker demographics. Speaker embeddings account for 58.9\% (95\% CI = [55.7, 61.9]) of variance in identity judgments, which is more than acoustic features, social attributes, and clone status combined. Once all these observed features are accounted for, clone status adds no additional predictive power. These results shows that the perceptual impact of voice cloning is positional rather than categorical: we can model how listeners judge a voice by how close it falls to the perceptual boundary that defines each speaker's recognizable voice, applying the same criterion to real and synthetic speech alike.
DATA SCIENCE NIGHTS are monthly meetings featuring presentations and discussions about data-driven science and complex systems, organized by Northwestern University graduate students and scholars. Students and researchers of all levels are welcome! For more information: http://bit.ly/nico-dsn
FUTURE DATES:
Data Science Nights will return in September!
Time
Thursday, May 28, 2026 at 5:30 PM - 7:00 PM
Location
M416, Technological Institute Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
Spring 2026 Commencement
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All Day
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Spring 2026 Commencement
Time
Sunday, June 14, 2026
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Juneteenth - University Closed
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All Day
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Juneteenth - University Closed
Time
Friday, June 19, 2026
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University Academic Calendar
Independence Day (observed) - University Closed
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All Day
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Independence Day (observed) - University Closed
Time
Friday, July 3, 2026
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Fall 2026 Classes Begin
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All Day
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Fall 2026 Classes Begin
Time
Wednesday, September 23, 2026
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