Links to Colloquia


Past years' colloquia

Eisenbud Lecture Series in Mathematics and Physics

Berko Symposium

All colloquium videos are under copyright and may not be reproduced, in part or in total, without written permission of the speaker and of the Physics Department.

Department Colloquia


Martin Weiner Lecture Series
Department of Physics Colloquium
4 pm, Abelson 131
Refreshments at 3:30 pm outside Abelson 131

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Fall 2017 Colloquia


Tuesday, September 5, 2017
Margaret Johnson, Johns Hopkins University
"Protein self-assembly in the cell: Spatial and temporal control through membrane localization"
Host: Michael Hagan
Abstract: Cell division, endocytosis, and viral budding would not function without the localization and assembly of protein complexes on membranes. What is poorly appreciated, however, is that by localizing to membranes, proteins search in a reduced space that effectively drives up concentration. We have derived an accurate and practical analytical theory to quantify the significance of this dimensionality reduction in regulating protein assembly on membranes. We define a simple metric, an effective equilibrium constant, that allows for quantitative comparison of protein-protein interactions with and without membrane present. We find that many of the protein-protein interactions between pairs of proteins involved in clathrin-mediated endocytosis in human and yeast cells can experience enormous increases in effective protein-protein affinity (10-1000 fold) due to membrane localization. By developing new methods for reaction-diffusion simulation of protein structures, we further characterize the non-equilibrium dynamics of these assembly processes, with reaction parameters defined from experiment. Both theory and simulations highlight the power of membrane localization in triggering robust protein-protein binding, suggesting that it can play an important role in controlling the timing of endocytic protein coat formation.


Tuesday, September 12, 2017
Michael Hagan, Brandeis University
Host: Physics Department
"How to control the size of a self-assembling, self-filling shell"
Abstract: The self-assembly of a protein shell around a cargo is a common mechanism of encapsulation in biology. For example, many viruses assemble an icosahedral protein shell (capsid) around the the viral nucleic acid. Some viruses then acquire an additional exterior coating by budding through a cell membrane. Similarly, bacterial microcompartments (BMCs) are large icosahedral protein shells that assemble around collections of enzymes to act as organelles inside of bacteria.

In this talk I will use coarse-grained computational models and simple scaling calculations to illuminate the factors that control such a self-assembly process. I will particularly focus on how material properties (such as nucleic acid electric charge, membrane bending modulus, or enzyme cohesive forces) control assembly pathways and the size of the assembled shell.


Tuesday, September 19, 2017
Daniel Whiteson, University of California, Irvine & Jorge Cham, PHD Comics
"We Have No Idea"
Host: Bjoern Penning
Abstract: Jorge and Daniel will talk about the big unsolved mysteries of the Universe, including dark matter, dark energy, and the behavior of cats. A fun presentation that combines science, humor, and live drawing, inspired by their new book.


Tuesday, September 26, 2017
Dapeng Bi, Northeastern University
"Mechanics of Epithelial Tissues: Structure, Rigidity and Fluidity"
Host: Bulbul Chakraborty
Abstract: Cells must move through tissues in many important biological processes, including embryonic development, cancer metastasis, and wound healing. Often these tissues are dense and a cell's motion is strongly constrained by its neighbors, leading to glassy dynamics. Although there is a density-driven glass transition in particle-based models for active matter, these cannot explain liquid-to-solid transitions in confluent tissues, where there are no gaps between cells and the packing fraction remains fixed and equal to unity. I will demonstrate the existence of a new type of rigidity transition that occurs in confluent tissue monolayers at constant density.  The onset of rigidity is governed by a model parameter that encodes single-cell properties such as cell-cell adhesion and cortical tension. I will also introduce a new model that simultaneously captures polarized cell motility and multicellular interactions in a confluent tissue and identify a glassy transition line that originates at the critical point of the rigidity transition. This work suggests an experimentally accessible structural order parameter that specifies the entire transition surface separating fluid tissues and solid tissues. 


Tuesday, October 3, 2017

No colloquium (Brandeis Thursday)


Tuesday, October 10, 2017
Tulika Bose, Boston University
Title and abstract: TBD


Tuesday, October 17, 2017
Elizabeth Blanton, Boston University
Host: John Wardle
Title and abstract: TBD


Tuesday, October 24, 2017

TBA


Tuesday, October 31, 2017
Huajian Gao, Brown University
Title and abstract: TBD


Tuesday, November 7, 2017
Narayanan Menon, UMass Amherst
Host: Michael Hagan
Title and abstract: TBD


Tuesday, November 14, 2017
Julie Williams-Byrd, NASA Langley Research Center
Host: Anique Olivier-Mason
Title and abstract: TBD


Tuesday, November 21, 2017

No colloquium (Thanksgiving week)


November 27-29, 2017
Eisenbud Lecture Series in Mathematics and Physics
James Sethna, Cornell University
Host: Bulbul Chakraborty
Title and abstract: TBD


Tuesday, December 5, 2017
Roxanne Guenette, Harvard University
Title and abstract: TBD


Spring 2018 Colloquia


Tuesday, January 16, 2018

Reserved.


Tuesday, January 23, 2018

Reserved.


Tuesday, January 30, 2018

TBA


Tuesday, February 6, 2018

Reserved.


Tuesday, February 13, 2018

Reserved.


Tuesday, February 20, 2018

No Colloquium (Midterm Recess)


Tuesday, February 27, 2018

TBA


Tuesday, March 6, 2018

No colloquium (APS)


Tuesday, March 13, 2018

TBA


Tuesday, March 20, 2017

TBA


Tuesday, March 27, 2018

TBA


Tuesday, April 3, 2018

No colloquium: Passover and spring recess


Tuesday April 10, 2018

TBA


Tuesday, April 17, 2018

TBA


Tuesday, April 24, 2018

TBA