PAST SCHEDULES

DECEMBER 3, 2020

TITLE AND ABSTRACT:

"Intracellular Transport of Intermediate Filaments Driven by Antagonistic Motor Proteins"

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Abstract:

 Intermediate filaments are one of the components of the cytoskeleton; they are involved in cell mechanics, signalling and migration. The organisation of intermediate filaments in networks is the major determinant of their functions in cells. Their spatio-temporal organization in cells results from the interplay between assembly/disassembly processes and different types of transport. 
For instance, intermediate filaments, which are long elastic fibers, are transported in cells along microtubules, another component of the cytoskeleton, by antagonistic motor proteins. How elastic fibers are efficiently transported by antagonistic motors is not well understood and is difficult to measure with current experimental techniques. Adapting the tug-of-war paradigm for vesicle-like cargos, a mathematical model is developed to describe the motion of an elastic fiber punctually bound to antagonistic motors. Combining stochastic and deterministic dynamical simulations and qualitative analysis, the asymptotic behaviour of the model, which defines the mode of transport of fibers, is studied [1,2]. The effects of initial conditions, reflecting the intracellular context, model parameters and functionals, describing motors and fiber properties, and noise, outlining other intracellular processes, are characterized. 
Work in collaboration with J. Dallon (BYU, Provo, Utah, USA), C. Leduc and S. Etienne-Manneville (Institut Pasteur, Paris, France)

[1] Dallon, J., Leduc, C., Etienne-Manneville, S., and Portet, S. Stochastic modeling reveals how motor protein and filament properties affect intermediate filament transport. J. Theor. Biol. 464: 132-148 (2019).
[2] Portet, S., Leduc, C., Etienne-Manneville, S., Dallon, J. Deciphering the transport of elastic filaments by antagonistic motor proteins. Phys. Rev. E. 99: 042414 (2019).

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SPEAKER: 

Stéphanie Portet, Professor at the University of Manitoba in the Department of Mathematics 

(Learn more about the speaker here​)

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WHEN:

Thursday, December 3, 2020

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Meet and Greet:

• 2:00pm-2:30pm CST

​Talk:

• 2:30pm-3:20pm CST 

Questions:

• 3:20pm-3:30pm CST

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WHEN:

The event took place via Zoom due to Covid-19 restricitons.

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Watch recorded talk here:

https://usask.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=94fe9617-2f0a-476d-9973-ac86017d83e7

NOVEMBER 5, 2020

TITLE AND ABSTRACT:

"Recent Trends on the Inverse Eigenvalue Problem for Graphs"

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Abstract:

Given a simple graph G=(V,E) with V = {1,2,...n}, we associate a collection of real n-by-n symmetric matrices governed by G, and defined as S(G) where the off-diagonal entry in position (i,j) is nonzero iff i and j are adjacent.

The inverse eigenvalue problem for G (IEP-G) asks to determine if a given multi-set of real numbers is the spectrum of a matrix in S(G). This particular variant on the IEP-G was born from the research of Parter and Wiener concerning the eigenvalue of trees and evolved more recently with a concentration on related parameters such as: minimum rank,maximum multiplicity, minimum number of distinct eigenvalues, and zero forcing numbers. An exciting aspect of this problem is the interplay with other areas of mathematics and applications. A novel avenue of research on so-called `strong properties' of matrices, closely tied to the implicit function theorem, provides algebraic conditions on a matrix with a certain spectral property and graph that guarantee the existence of a matrix with the same spectral property for a family of related graphs.

In this lecture, we will review some of the history and motivation of the IEP-G. Building, on the work Colin de Verdi\'ere, we will discuss some of these newly developed `strong properties' and present a number of interesting implications pertaining to the IEP-G.

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SPEAKER: 

Shaun M. Fallat, Professor at the University of Regina in the Department of Mathematics and Statistics 

(Learn more about the speaker here​)

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WHEN:

Thursday, November 5, 2020

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Meet and Greet:

• 2:00pm-2:30pm CST

​Talk:

• 2:30pm-3:20pm CST 

Questions:

• 3:20pm-3:30pm CST

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WHERE:

The event took place via Zoom due to Covid-19 restrictions.

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Watched recorded livestream here: