ICTP Quantitative Life Sciences Section - Upcoming seminars

[Quantitative Life Sciences]

Tuesday, 29 March at 14:00

ICTP, Central Area, 2nd floor, old SISSA building

Speaker: Armita Nourmohammad (Carl Icahn Laboratory, Lewis Sigler 
Institute, Princeton University, USA)

Title: *Statistical Physics of Molecular Evolution*

Abstract: Molecular phenotypes, such as gene expression levels or 
protein binding affinities, are increasingly accessible to quantitative 
measurements. Such phenotypes measure molecular functions and are 
important targets of natural selection. However, the map between 
encoding DNA sequences and molecular phenotypes is often too difficult 
to quantify. This lack of knowledge raises an obvious question: which 
evolutionary properties of a phenotype are universal, that is, 
independent of the molecular details? In this talk, I will show that 
universality is an emerging property of complex phenotypes, which are 
encoded by multiple genomic loci. I will introduce a non-equilibrium 
framework for adaptive dynamics of such phenotypes in time-dependent 
environments, and between co-evolving populations. In time-dependent 
environments, changes in the environment drive the evolution of the 
species, but not vice versa. As an example, I will present strong 
evidence that adaptation dominates the evolution of gene expression 
levels in Drosophila. Co-evolving populations reciprocally affect the 
fitness of each other, acting as time-dependent environments with 
feedback. As an example, I will show evidence of co-adaptation between 
interacting cellular populations of HIV viruses and the antibody 
repertoire of a patient over the course of an infection. In particular, 
I will discuss the conditions for emergence of highly potent broadly 
neutralizing antibodies, which are now recognized as critical for 
designing an effective vaccine against HIV.

Web page: http://indico.ictp.it/event/7837/

*****************************************************************

Thursday, 31 March at 16:00

ICTP, Central Area, 2nd floor, old SISSA building

Speaker: Saeed Saremi (The Salk Institute for Biological Studies, La 
Jolla, CA, USA)

Title: *Problems in physics, machine learning, and computational 
neuroscience with many scales of length *

Abstract:  Natural images are scale invariant, with structures that span 
a vast range of length scales – from the smallest within a few dozen 
pixels to large structures the size of the image itself. In this talk, I 
will present a novel statistical mechanical model of natural images 
rooted in the theory of critical phenomena that sheds light on this 
hierarchy of length scales, paving the road for a (nonequilibrium) 
statistical model of natural images with few parameters. Studies of 
natural image statistics were first done in neuroscience but have since 
become of immense interest in machine learning due to the recent 
advances in deep learning. My research on natural images fits into a 
bigger picture: the general and common problem of "many scales of 
length" in physics, machine learning and neural coding.

Web page: http://indico.ictp.it/event/7833/


-- 
Erica Sarnataro
Group Secretary
Quantitative Life Sciences
The Abdus Salam International Centre for Theoretical Physics (ICTP)
Trieste,  Italy
Tel. +39-040-2240623
e-mail:qls at ictp.it