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STEM Scholars Lecture Series
The STEM Scholars lectures are designed for the general public. These lectures bring together area K-12 and community college students, faculty, and administrators; local business and industry leaders; CSUS students, faculty and alumni; and local community members to learn more about Sacramento State faculty research and scholarly efforts in STEM fields. The lectures cover a wide range of STEM topics from artificial intelligence to environmental sustainability issues.
Upcoming Lecture
Math Meets Biology: Modeling Vector-Bone Diseases Across Species
Free Community Lecture, Wednesday, October 1st 2025
Lecture from 6:00-7:00 PM in Sequoia Hall, Room 301
Reception from 5:45-6:00 PM in Sequoia Hall, Room 320
Abstract:
Many diseases that affect humans, animals, and even insects are not transmitted directly--they rely on other organisms, such as mosquitoes or ticks, to spread. These are referred to as vector-borne diseases, and they can have signaficant public and ecological impacts. In this talk, I will provide a brief overview of my research program, followed by an introduction to the basics of SIR models and how they help us understand the spread of these diseases. I will focus on virus transmission within a honeybee colony, specifically transmitted by Varroa destructor.
I will also briefly discuss mathematical models of Lyme disease, transmitted to humans through the bite of infected black-legged ticks, and malaria, caused by Plasmodium, parasites and transmitted via bites from infected female Anopheles
mosquitoes. These models are analyzed using a combination of analytical and computational techniques. Using computer Simulations, we investigate disease transmission over time based on our models. For example, a virus-infested honeybee colony without varroacide treatment collapses regardless of the of the forager mortality rate. Our results aim to assist beekeepers in designing effective remedial strategies.
Dr. Vardayani Ratti is an Assistant Professor of Mathematics at California State University, Sacramento, specializing in mathematical biology and epidemiological modeling. Her research applies differential equations to study complex biological and ecological phenomena, including infectious diseases, pollinator health, and gene-based HIV treatments. Dr. Ratti earned her Ph.D. in Mathematics from the University of Guelph in Canada, where she focused on modeling disease dynamics in honeybee colonies. Prior to joining Sac State, she held a postdoctoral position at Dartmouth College as a John Wesley Young Research Instructor.
Past Lecture
The Roots of Our Modern World: Archaeological Perspectives on the Emergence of Complex Society
Abstract:
Anatomically modern humans have existed on this planet for roughly 300,000 years. For the first 97% of that existence, we lived in small, mobile groups with only minimal levels of differentiation. But beginning around 8,000 years ago, we set about developing complex systems of social organization based on political hierarchy, wealth and status inequality, and economic specialization and interdependence. These developments facilitated the growth of the world’s first regional-scale polities, often referred to as chiefdoms, and in some instances laid the organizational groundwork on which ancient states and modern nations would eventually be built. Comparative exploration of how these early complex societies developed can provide valuable insight into the evolutionary roots of our own, modern world, and reveal how the forces that shaped early complex society evolution continue to shape societies today. This talk engages in such exploration using work carried out by the Chiefdom Datasets Project, a large-scale, collaborative comparison of early complex societies from around the world.
Bio:
Assistant Professor Adam Berrey is an anthropological archaeologist who specializes in the comparative study of early complex societies. His research focuses on understanding the interplay between demographic, economic, and sociopolitical processes as systems of organization based on hierarchy, inequality, and economic specialization were first beginning to emerge. Professor Berrey explores these processes from a multiscalar and comparative perspective and through the quantitative and spatial analysis of archaeological data. He has directed archaeological field research in central and eastern Panama that has been funded by the National Science Foundation. At Sacramento State, Professor Berrey teaches classes on quantitative data analysis, archaeological theory, and ancient societies of the Americas.
Professor Berrey has a B.A. and Ph.D. in Anthropology from the University of Pittsburgh. He is a Research Associate at the Smithsonian Tropical Research Institute in Panama City, Panama, and from 2017 to 2021 was a postdoctoral researcher in the Department of Anthropology at the Universidad de los Andes in Bogotá, Colombia. He joined the Department of Anthropology at Sacramento State in the Fall of 2021.