Category Archives: Biopolymers

Congratulations Joe Lopes – CREST fellow spring 2017

Congratulations go to Joe, who was selected as one of just four UC Merced graduate students to recieve funding for the Spring semester as a CREST fellow.


The CREST center (Center for cellular and biomolecular machines) is funded by the National Science Foundation and you can read more about their work and opportunities here.

Joe is working on kinesin – based  microtubule transport and active matter.

Microtubules gliding on kinesin motors





Studying microtubule spools

Understanding the role of transport velocity in biomotor-powered microtubule spool assembly

Amanda J. Tan, Dail E. Chapman, Linda S. Hirst and Jing Xu

In this new paper we examined the sensitivity of microtubule spools to transport velocity.
Perhaps surprisingly, we determined that the steady-state
number and size of spools remained constant over a seven-fold
range of velocities. Our data on the kinetics of spool assembly
further suggest that the main mechanisms underlying spool growth
vary during assembly.
Read the paper in RSC Advances here

Amanda Tan – winner 2016 faculty mentor fellowship

Congratulations to physics graduate student Amanda Tan for winning a UC Merced “faculty mentor” fellowship.  This prestigious fellowship is awarded to prepare future faculty and provides a year’s funding plus a travel stipend.

Amanda’s research project focuses on active biological materials, in particular microtubules and molecular motors. She is collaborating with the Xu lab at UC Merced and will have her first paper with the group out soon.

The award assists recipients in acquiring and developing advanced research skills under faculty mentorship and is aimed at increasing the number of students who complete their Ph.D. degree and successfully acquire a faculty appointment.



Congratulations Dr Pandolfi!

Congratulations go to Ron Pandolfi, the latest PhD graduate from the Hirst group. Ron’s PhD defense was on Monday Dec 8th, where he presented his thesis on “Self-assembly and Design of Tunable Soft Materials”

During his time in the lab Ron’s work has included molecular dynamics simulations of semi-flexible polymers and x-ray characterization of different soft systems.

Ron was recently hired at the Advanced Light Source, Lawrence Berkeley National Lab in Berkeley, CA where he’ll be working with soft matter x-ray team.




Designing highly tunable semi-flexible filament networks

“Designing highly tunable semi-flexible filament networks”

R. Pandolfi, L. Edwards, D. Johnston, P. Becich and L.S. Hirst, PHYS. REV. E. 89, 062602(2013) Link

Semiflexible polymers can generate a range of filamentous networks significantly different in structure from those seen in conventional polymer solutions. Our coarse-grained simulations with an implicit cross-linker potential show that networks of branching bundles, knotted morphologies, and structural chirality can be generated by a generalized approach independent of specific cross-linkers. Network structure depends primarily on filament flexibility and separation, with significant connectivity increase after percolation. Results should guide the design of engineered semiflexible polymers