University of Denver Spring 2025

PUBLIC GOOD

Unlocking how HIV spreads Virologist and biophysicist Schuyler van Engelenburg is one step closer to understanding how HIV spreads once it enters the human body, thanks to a new grant from the National Institutes of Health. For years, his team has developed new microscopes so they could visualize the virus replication process on a single-molecule basis. “Surprisingly, this has been a

challenging aspect of the viral infection cycle to study, and it's really because it requires a multidisciplinary kind of approach—bringing in aspects of cell biology, virology, biochemistry and, in my laboratory, optical imaging,” he says. Van Engelenburg plans to further develop and utilize specific instruments to better understand the mechanisms of virus transfer. One key part of this process is the envelope glycoprotein (Env), which attaches HIV to the cells it infects and plays a crucial role in fusing the virus with healthy cells. Scientists don’t fully understand how Env gets incorporated into the virus or how it helps the virus spread from one cell to another. WHY IT MATTERS: This research will help others create antiretroviral treatments that specifically target and disrupt the process in the early stages. There are currently no drug treatments that target this stage of assembly. Solving a 70-year-old math problem Associate Professor Mandi Schaeffer Fry will be the first faculty member since the 1880s to be published in the Annals of Mathematics, widely seen as the industry’s most prestigious journal. Schaeffer Fry helped complete a problem that dates back to 1955—mathematician Richard Brauer’s Height Zero Conjecture. Over the years, number crunchers have worked on the problem at universities across the globe, and some found partial solutions; however, the problem was not completed until now.

Fry and her collaborators—University of Kaiserslautern professor Gunter Malle,

University of Valencia professor Gabriel Navarro and Rutgers University professor Pham Huu Tiep—worked around the clock over the course of three months in eight-hour shifts during the summer to find a solution. In 2023, the work was accepted for publication. The problem relates to groups, or collections of things that follow certain rules when combined, kind of like the way numbers follow rules in addition or multiplication. Mathematicians wanted to know if you could look at a table of data about a group and use it to figure out something about smaller pieces of that group, called “defect groups.” These smaller pieces are like mini groups that help us understand the bigger group. Brauer's Height Zero Conjecture was the first conjecture that led to the study of “local-global” problems, which seek to relate properties of groups with those of smaller subgroups, Schaeffer Fry says—“letting us 'zoom in' on the group using just a specific prime number and simplify things." WHY IT MATTERS: Fry and her colleagues proved the conjecture is true, which helps mathematicians understand more about how groups work and makes solving other problems easier.

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UNIVERSITY OF DENVER MAGAZINE | SPRING 2025