Journal of Biological Physics Webinar Series

The editors of Journal of Biological Physics are proud to present a series of webinars organized by the journal.

Stay tuned for the next webinar announcement!

If you have any questions, contact Jack Manzi at jack.manzi@springer.com


Previous Webinars

Landscape and flux theory for nonequilibrium biological systems

Speaker: Professor Jin Wang, Stony Brook University

Originally Presented on: 20 July 2021

Recording: View a Recording of the Webinar Here.

Abstract:

In this talk, I will review recently developed landscape and flux theory as well as its biophysical applications. Together with concepts and tools developed in other areas of nonequilibrium physics, significant progress has been made in unraveling the principles underlying efficient energy transport in photosynthesis, cellular regulatory networks, cellular movements and organization, cell cycle, differentiation and development, cancer, neural network dynamics, population dynamics and ecology, aging, immune responses,  and evolution. Here recent advances in nonequilibrium physics are reviewed and their application to biological systems is surveyed. Many of these results are expected to be important as the field continues to build our understanding of life. 

Non-Gaussian Statistics

Speaker: Professor Ralf Metzler, University of Potsdam

Originally Presented on: 6 July 2021

Recording: View a Recording of the Webinar Here.

Abstract:
Brownian yet non-Gaussian diffusion, characterised by a linear scaling in time of the mean squared displacement but a non-Gaussian displacement distribution is a phenomenon that has been observed in a variety of systems. In my talk, after a brief historical introduction to Brownian motion I will review experimental evidence and show how non-Gaussian statistics emerge from random-parameter models, extreme value arguments, and other models. In particular, I will also talk about quenched versus annealed disorder and demonstrate how shape-shifting in tracers leads to time-fluctuating diffusivities. I will finally address anomalous diffusion systems dominated by viscoelasticity in heterogeneous environments, for which non-Gaussian displacement distributions are measured.

Biological physics of chromatin structure and dynamics 

Speaker: Professor Alexandre V. Morozov, Rutgers University

Originally Presented on: 22 June 2021

Recording: View a Recording of the Webinar Here.

Abstract:
Inside cell nuclei in eukaryotic organisms, genomic DNA is packaged into arrays of nucleosomes. Each fully wrapped nucleosome consists of 147 base pairs of DNA wrapped around a histone octamer core. The resulting complex of DNA with histones and other proteins forms a multi-scale structure called chromatin. At the most fundamental level of chromatin organization, arrays of nucleosomes form 10-nm fibers that are thought to resemble beads on a string. Chromatin fibers fold into higher-order structures which ultimately make up functional chromosomes. Depending on the organism and the cell type, 75-90% of genomic DNA is packaged into nucleosomes. The question of how various cellular functions such as gene transcription are carried out on the chromatin template is an outstanding puzzle in eukaryotic biology. In this talk, I will discuss recent advances in understanding fundamental biophysical mechanisms of chromatin equilibrium and non-equilibrium dynamics. In particular, I will demonstrate that in baker's yeast, neighboring nucleosomes invade each other's territories through DNA unwrapping and translocation, or through initial assembly in partially wrapped states. Thus, the classic "beads-on-a-string" picture of well-positioned, non-overlapping nucleosomes must be supplanted by a more dynamic view in which nucleosomes, aided by chromatin remodelers, transiently assemble and disassemble, translocate, and interact with each other and with other chromatin components such as regulatory factors and transcriptional machinery.

Biophysics of Amyloid β-Protein Oligomer Formation of Relevance to Alzheimer's Disease

Speaker: Professor Brigita Urbanc, Drexel University

Originally presented on: 18 May 2021

Recording: View a Recording of the Webinar Here.

Abstract:
Substantial evidence implicates soluble oligomers formed by intrinsically disordered amyloid β-protein (Aβ) as central to Alzheimer's disease pathology, yet their structural characteristics that may be the cause of membrane damage remain poorly understood. I will elucidate different biophysical approaches aimed at unraveling structure-function relationship of Aβ oligomers and provide insights into novel developments that challenge our notion of Aβ self-assembly as an exclusively pathological process.

Mapping the landscapes of cancer

Speaker: Professor Gábor Balázsi, Stony Brook University

Originally presented on: 20 April 2021

Recording: View a Recording of the Webinar Here.

Abstract:
Cancer drug resistance or metastasis can be visualized as cells exploring fitness landscapes. I will illustrate the utility of fitness landscapes in understanding oncogenic processes and provide examples of how we can infer such landscapes experimentally with the help of noise-controlling synthetic gene circuits in human cancer cells.