Events
Past Event
WED@NICO WEBINAR: Lightning Talks with Northwestern Fellows and Scholars!
Northwestern Institute on Complex Systems (NICO)
12:00 PM
Details
Description:
NICO is hosting a lightning talk seminar each term as a part of our Wednesdays@NICO seminar series. Northwestern graduate students and postdoctoral fellows are invited to participate. To sign up for future lightning talks, please visit: https://bit.ly/2lRqSXK
Webinar:
Webinar link: https://northwestern.zoom.us/j/96018513447
Passcode: nico
ID: 960 1851 3447
Speakers:
Jaehyuk Park
Postdoctoral Fellow
Kellogg School of Managmeent, and
Northwestern Institute on Complex Systems
Emma Zajdela
PhD Candidate
Department of Engineering Sciences and Applied Mathematics
McCormick School of Engineering
Gary Nave
Postdoctoral Fellow
Department of Engineering Sciences and Applied Mathematics
McCormick School of Engineering
Sarah Ben Maamar
Postdoctoral Fellow
Department of Chemical and Biological Engineering
McCormick School of Engineering
Talk Titles and Abstracts:
Jaehyuk Park "People, Places, and Ties: Landscape of social places and their social network structures"
Due to their essential role as places for socialization, “third places”—social places where people casually visit and communicate with friends and neighbors—have been studied by a wide range of fields including network science, sociology, geography, urban planning, and regional studies. However, the lack of a large-scale census on third places kept researchers from systematic investigations. Here we provide a systematic nationwide investigation of third places and their social networks, by using Facebook pages. Our analysis reveals a large degree of geographic heterogeneity in the distribution of the types of third places, which is highly correlated with baseline demographics and county characteristics. Certain types of pages like “Places of Worship” demonstrate a large degree of clustering suggesting community preference or potential complementarities to concentration. We also found that the social networks of different types of social place differ in important ways: The social networks of ‘Restaurants’ and ‘Indoor Recreation’ pages are more likely to be tight-knit communities of pre-existing friendships whereas ‘Places of Worship’ and ‘Community Amenities’ page categories are more likely to bridge new friendship ties. We believe that this study can serve as an important milestone for future studies on the systematic comparative study of social spaces and their social relationships. This is joint work with Bogdan State (scie.nz), Monica Bhole (Facebook), Michael Bailey (Facebook), and Yong-Yeol Ahn (Indiana Univ.).
Emma Zajdela "Catalyzing Collaborations: A Model for the Dynamics of Team Formation at Conferences"
The COVID-19 pandemic has brought to the fore the importance of collaboration among scientists to address challenges of global significance. One of the main ways that new and innovative collaborations are catalyzed is by gathering scientists together at conferences. In the U.S. alone, conferences amount to billions of dollars per year in terms of travel expenses, organizing costs, and loss of research time. In this lightning talk, I present a dynamical model for predicting the formation of scientific collaborations at conferences, inspired by the chemical process of catalysis. Specifically, the model tracks the probability that two participants at a conference will form a collaboration given their previous knowledge of each other and level of interaction throughout the conference. Model predictions are tested using data from two multi-year series of interactive conferences known as the Scialog Conferences, organized by the Research Corporation for Science Advancement over the period 2015-2020. We find that scientists who interact more intensely throughout the conference have a higher likelihood of forming a collaboration. Furthermore, we find that the likelihood of collaborating remains at a higher level even after the interaction between participants has ceased. Our findings may have an impact on stakeholders from public, private, and nonprofit sectors who wish to optimize future conferences to promote new collaborations.
Gary Nave "Approximating attracting and repelling flow features with the trajectory divergence rate"
Within the flow of a fluid or a dynamical system, there are often attracting or repelling manifolds that provide an organizing “skeleton” to the flow. These structures have been shown to be barriers to transport of material moving within a flow. In this talk, I will introduce the trajectory divergence rate, which can serve to rapidly approximate attracting and repelling structures using only the vector field. By looking at the instantaneous growth rate of normal vectors, we measure the rate at which adjacent trajectories are coming together or moving apart. This diagnostic can be applied to, for example, slow manifolds, ocean flows, and limit cycle oscillations, and provides an intuitive understanding of the geometric organization of a flow.
Sarah Ben Maamar "Comprehensive analysis of the reproducibility of RNAseq computational pipelines"
Sarah Ben Maamar, Reese Richardson, Sophia Liu, Luis Nunes A. Amaral.
Next generation sequencing technologies revolutionized biomedical research and became unavoidable due to their low costs, high amount of data generated and the wide variety of their applications. In particular, RNA-sequencing (RNA-seq) has become widely used in biological and biomedical fields as this technique allows the evaluation of gene expression levels in model organisms under different contexts. These contexts include the comparison of sick versus healthy cells; the effect of specific drugs on cells gene expression; monitoring of changes in gene expression over time; or the discovery of the potential role of an unknown gene when comparing different tissues.
As the output of RNA-seq is complex and large, processing and analysis of such data requires the use of complex computational pipelines involving multiple steps and softwares to make the data comprehensible. RNA-seq computational pipelines vary according to the application and can have up to six steps, for which up to ten different softwares are available for each task. Each software also offers multiple parameters to better tune the analysis for each application and dataset.
Despite the endless choices, there is currently no standardized pipeline agreed upon in the broad biomedical field. Thus, unless a computational pipeline used to process a dataset is thoroughly documented, it is almost impossible to reproduce the results obtained from a dataset after processing.
In this work, we analyze the documentation and replicability associated to each step of RNA-seq computational pipelines used to study differential gene expression in the model bacteria Escherichia coli. We particularly assess the intrinsic bias introduced by the use of each software for each step as well as the bias associated to each parameter choice. Interestingly, we found two to three steps of RNA-seq computational pipeline are particularly undermining the comparability of the results between studies. We are currently in the process of quantifying the biases at each step of the different computational pipelines and this talk will present some of our results.
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. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, March 3, 2021 at 12:00 PM - 1:00 PM
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Michelle Birkett, Feinberg School of Medicine "Structural Inequities across Layers of Social Context as Drivers of HIV"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Michelle Birkett, Associate Professor, Department of Medical Social Sciences, Feinberg School of Medicine, Northwestern University
Title:
Structural Inequities across Layers of Social Context as Drivers of HIV
Abstract:
Black young men who have sex with men (YMSM) experience massive HIV disparities but the reasons for these disparities are unknown. In this talk I describe our approach to understanding these disparities through the measurement of the social and contextual systems around individuals. Specifically, through utilizing empirical data we have produced large-scale simulations of the movements and sexual partnerships of a synthetic population of YMSM and transgender women in Chicago. Our results indicate racial differences in the places where folks spend time, and suggest that differences in collocation facilitate infectious disease disparities by shaping sexual partnership in ways which pool HIV risk.
Speaker Bio:
Michelle Birkett is a tenured associate professor in the Departments of Medical Social Sciences and Preventive Medicine. She directs the Center for Computational and Social Sciences in Health (COMPASS) within the Institute for Artificial Intelligence in Medicine (I.AIM), which aims to foster connection between data science, social science and population health across Northwestern. For nearly 10 years she directed the CONNECT Complex Systems and Health Disparities Research Program within the IMPACT Institute. Dr. Birkett’s research uses network and quantitative methodologies to understand the social contextual influence of stigma on the health and wellbeing of marginalized populations, and in particular, sexual and gender minority youth. This work is influenced by a multilevel perspective of health that considers direct and indirect influences of multiple levels of the social and physical environment. This multilevel approach to understanding health underlies her interest in network data and her commitment to conducting research that leads to social change at multiple levels of society to eliminate health disparities.
Dr. Birkett has led multiple NIH-funded projects and has a wealth of expertise in the collection and analysis of network data. She is an NIH Career Awardee for her work understanding network, multilevel, and contextual influences on racial disparities in HIV within young men who have sex with men. She also directs Network Canvas, a software development project which seeks to simplify the collection and streamline the management of social data, thereby allowing health researchers to assess more nuanced associations between social contextual factors and disease. An author of more than 85 articles, Birkett's work has appeared in academic journals like The American Journal of Public Health, The Journal of Acquired Immune Deficiency Syndrome, The Journal of Adolescent Health, Social Networks, as well as popular outlets such as The Atlantic, Reuters, and Wired. In 2018 she was selected as an inaugural member of the New Voices Program of The National Academies of Sciences, Engineering, and Medicine, a initiative to promote new and diverse scientific voices within the National Academies.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/92223012626
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. 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.
Time
Wednesday, April 22, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Gary Slutkin, Cure Violence Global "The End of Violence - How do we do that?" (co-sponsored with CORNERS)
Northwestern Institute on Complex Systems (NICO)
12:00 PM
//
Lower Level, Chambers Hall
Details
Speaker:
Gary Slutkin, Founder, Cure Violence Global
Title:
The End of Violence - How do we do that?
Abstract:
Dr. Slutkin will discuss the msin findings in his new book “The End of Violence”
After 20 years fighting epidemics of infectious diseases in the U.S., and abroad with the World Health Organization, Dr. Slutkin returned to Chicago and saw violence acting the same way as these other diseases. He then founded Cure Violence Global to show that violence not only behaves like other epidemics, but its spread can be interrupted and stopped using the same playbook. This approach is now being used widely and for many types of violence.
In this book, Dr. Slutkin reveals how we can now understand how violence spreads from person to person and from country to country, through invisible brain processes that can now be identified. He also found that both the contagion, and its interruption, can work for all forms of violence from child abuse to community violence, violence against women, suicide, and even war, genocide and tyranny. The book provides stories and data on success for several of these different forms of violence in Chicago, Baltimore, NYC, Honduras, Mexico, Colombia, Iraq, Syria and even to stop a potential nuclear war between the U.S. and North Korea.
With this new book, we now have not only a new diagnosis of violence – a disease - but a new method to stop it – with results in dozens of communities and countries, as well as a whole new understanding, language and even a whole new set or workers.
Speaker Bio:
Gary Slutkin is a physician and epidemiologist formerly of the World Health Organization, the Founder and CEO of Cure Violence, and an innovator in epidemic management, public health, behavior change, and data-based approaches to local and global problems.
He led or co-led efforts to reverse epidemics of tuberculosis and cholera in 40 refugee camps, led the efforts to start the national AIDS programs with the 13 countries in the epicenter of the epidemic in central and East Africa and, led World Health Organization’s efforts to reverse the AIDS epidemic in Uganda, the only country to successfully reverse its AIDS epidemic at the time.
After 10 years abroad, Dr. Slutkin returned home to the U.S. and shifted his focus to violence, seeing it as an epidemic process. He is credited with having fully revealed the scientific and practical links for seeing and treating violence as a standard health epidemic. In the year 2000 he founded Cure Violence which has achieved 40% to 70% drops in violence in communities around the world using these methods. The approach has also been successfully adapted to curtail political violence, election violence, and gender-based violence in countries around the world.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/93101362874
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. 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.
Co-Sponsor:
This speaker is co-sponsored with CORNERS.
Time
Wednesday, April 29, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Daniel Stouffer, Leibniz Institute "Conceptual and Theoretical Challenges in the Study of Multi-Species Coexistence"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Daniel B. Stouffer, Research Group Leader, Department of Evolutionary and Integrative Ecology, the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
Title:
Conceptual and Theoretical Challenges in the Study of Multi-Species Coexistence
Abstract:
The population dynamics of most ecological communities unfold on temporal scales that cannot be fully studied in the laboratory or field. The generation times of trees, for example, are so long and varied that we may need to wait decades to determine how a whole, interconnected forest community responds to a changing climate. Many researchers thus use models to generate predictions that go beyond the bounds of what is experimentally tractable. To do so, it has become common to follow the "model-paramerisation paradigm". For example, a researcher interested in forest dynamics would not conduct long-term experiments to directly probe whether one tree species is ever competitively excluded by any other(s). Instead, they would use data from shorter-term experiments to estimate the parameters of a presupposed model, and then study whether or not their empirically parameterised model predicts competitive exclusion or coexistence. As powerful as this perspective has proven to be, it routinely hinges on multiple key assumptions that limit its versatility. I will describe recent and ongoing work that challenges these assumptions, while also describing some unexpected hurdles encountered along the way.
Speaker Bio:
Daniel B. Stouffer is a Research Group Leader in the Department of Evolutionary and Integrative Ecology at the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany. His group adopts a variety of computational, statistical, and analytical approaches to overcome ecological communities' innate complexity while exploring fundamental biological questions. They work on a variety of topics and systems and are particularly interested in understanding the emergent ecological and evolutionary consequences that arise due to interactions between species.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/98364690035
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. 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.
Time
Wednesday, May 6, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Hamsa Bastani, Wharton School, University of Pennsylvania "Challenges in Achieving Human-AI Collaboration"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Hamsa Bastani, Associate Professor of Operations, Information, and Decisions, and Statistics and Data Science, Wharton School, University of Pennsylvania
Title:
Challenges in Achieving Human-AI Collaboration
Abstract:
TBA
Speaker Bio:
Hamsa Sridhar Bastani is an Associate Professor of Operations, Information, and Decisions (OID) and Statistics and Data Science at the Wharton School of the University of Pennsylvania, where she co-direct the Wharton Healthcare Analytics Lab. Her research sits at the intersection of machine learning, operations research, and economics. She studies how to design, deploy, and evaluate AI systems that empower human decision-makers and improve societal outcomes.
Professor Bastani aims to combine methodological depth with implementation in consequential environments. She has worked with national governments to deploy algorithms at the country scale for targeted border COVID-19 screening and essential medicine access, and has co-led one of the first large field studies of generative AI tutors in high school mathematics. She studies both the mathematical properties of algorithms and the way people respond to them.
Her research has been published in leading outlets including Nature, Management Science, Operations Research, and PNAS, and has garnered numerous recognitions, including the Wagner Prize for Excellence in Operations Research, the INFORMS Pierskalla Award for best healthcare paper, and the George Nicholson Prize. Previously, she graduated summa cum laude from Harvard in 2012 with an A.M. in physics and an A.B. in physics and mathematics, completed her PhD in Stanford's Electrical Engineering department under the supervision of Mohsen Bayati, and spent a year as a Herman Goldstine postdoctoral fellow at IBM Research.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/99847338986
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. 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.
Time
Wednesday, May 13, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Lightning Talks with NU Scholars!
Northwestern Institute on Complex Systems (NICO)
12:00 PM
//
Lower Level, Chambers Hall
Details
NICO is looking for participants to share 12-15 minute lightning talks on their current research. To sign up, please fill out this short survey. These are open to Northwestern graduate students, postdoctoral fellows, and visiting scholars!
All talks will be given in person at Chambers Hall and this event will also be livestreamed via Zoom.
Speakers will be balanced based on their topics/disciplines in order to provide a broad representation of the research activities at NICO
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/98031689779
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. 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.
Time
Wednesday, May 20, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)