CMSP Seminar (Atomistic Simulation Webinar Series): TOMORROW 23 February at 11:00 a.m., Prof. Ali Naji

[CMSP Seminars Secretariat]

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Atomistic Simulation Webinar Series
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WEBINAR_

via Zoom



** * * TOMORROW, Wednesday, 23 February 2022 at 11:00 a.m.*** * **

Speaker:*Prof. Ali Naji *(Institute for Research in Fundamental 
Sciences, Iran)


Title:***Electrostatics with correlations and quenched disorder with 
implications for biomolecular interactions
*

Register in advance at:
https://zoom.us/meeting/register/tJwkdO2srzgjG9eJIldapkTpbYszm6QmiPHk
After registering, you will receive a confirmation email containing 
information about joining the seminar.


_Abstract_:

Coulomb interactions contribute significantly to the effective forces 
that act between molecular constituents of life such as proteins, 
biopolymers and membranes. Macromolecular and other contact surfaces in 
the soft and biomatter contexts are often heterogeneously (or even 
randomly) charged and their interactions are mediated through aqueous 
Coulomb fluids that often contain highly charged species entailing 
statistical correlations and electrostatic surface couplings. Yet, 
electrostatic theories dealing with these systems mostly rely on 
textbook models where surface charge distributions are treated as 
uniform (or regularly patterned) and the surrounding Coulomb fluid is 
treated as a mean-field medium described by traditional 
Poisson-Boltzmann-type approximations. Non-mean-field effects become 
relevant especially when the Coulomb fluid involves multivalent ions. In 
this talk, I will discuss how the theoretical advances made in 
describing electrostatics of non-mean-field phenomena in the said 
contexts (e.g., formation of large bundles of like-charged biopolymers 
such as F-actin and microtubules and condensation of DNA in bulk and in 
viruses) have led to a major paradigm shift in the electrostatic theory 
of charged fluids where likes can attract, opposites can repel and 
net-neutral (albeit randomly charged) objects can do both. When strong 
electrostatic couplings transpire in the presence of quenched surface 
charge disorder, an otherwise standard electrical double layer can 
become antifragile and lose entropy upon increasing the disorder 
strength even as it becomes thermodynamically more stable.


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CMSP, Condensed Matter & Statistical Physics Section
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The Abdus Salam International Centre for Theoretical Physics
https://www.ictp.it/

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