LDRD seminar: Sept. 11

Dionysios Antonopoulos

“Biofilms and Surfaces: Studying How Microorganisms Attach to and Influence Their Immediate Environment,” by Microbial Systems Biologist Dionysios Antonopoulos (BIO)

Abstract

Biofilms are a prevalent form of microbial life and can form on a wide range of material surfaces, from natural surfaces to human-made metals, concretes, plastics or resins. Naturally occurring microbial community assembly typically follows environmental cues; however, chemical and physical properties affect biofilm development and persistence. Because microorganisms naturally occur as communities, there are potentially multiple models for biofilm formation in different settings. Not understood are what environmental component(s) specifically trigger biofilm formation to begin with, what subsequent combination of biotic-abiotic interactions ultimately maintain and keep biofilms in check, and what effect these processes have on the degradation of the surfaces to which they are attached. This project is focused on developing an experimental platform and workflow to investigate the role of biofilms in material surface degradation. I will discuss our efforts to create an observational platform to visually track members of a community during this process, which will allow us to model how microbial populations coordinate their activities within a community to alter their local environment.

Biography

Dionysios Antonopoulos is a microbiologist and staff scientist studying how communities of microorganisms live and thrive together in a variety of environments. Currently, he is interested in understanding how microbial communities maintain their stability in a variety of environments. Stability is likely the result of “functional redundancy” via ultra-high levels of microbial community diversity. In this model, an increase in the redundancy of specific functions exhibited by the community contributes to its ability to resist perturbation. Antonopoulos’ group has created sub-community levels of organization (“minimal communities”) in the laboratory from several natural environments, in order to understand the building blocks of stability in these systems. In addition to his duties at Argonne, Antonopoulos is also an assistant professor in the Section of Gastroenterology, Department of Medicine at the University of Chicago and is director of the Enteric Microbiology Component of the Digestive Diseases Research Core Center there. The focus of his research at both institutions is on understanding how natural microbial communities “boot up” in the first place.

Qi Zhang

“Ultrafast Spin and Charge Dynamics in Two-Dimensional Systems,” by Argonne Scholar Qi Zhang (XSD)

Abstract

Charge and spin are the two fundamental degrees of freedoms of electrons utilized in modern computation and information storage technology. Understanding and controlling the spin-charge dynamics and their interconversion plays a central role in the field of spintronics.  In this talk, we will demonstrate ultrafast spin-charge conversion at various 2-D interfaces up to THz frequency. We will also unveil the strong spin-lattice and spin-charge interactions in the 2-D van der Waals magnets.

Biography

Qi Zhang earned his Ph.D. in applied physics from Rice University in 2015. He is currently an Alexei Abrikosov postdoctoral fellow in the X-ray Science Division.  His research focuses on understanding and controlling low-energy excitations in condensed matter systems, by spectroscopy method to including terahertz spectroscopy, light scattering and ultrafast laser techniques.

James Davis

“A Global Survey of CRISPR-Cas Systems in Archaeal and Bacterial Species,” by Computational Biologist James Davis (DSL)

Abstract

The CRISPR/Cas9 system has obtained widespread use as a genetic engineering tool and had facilitated efficient editing in genomes that used to be difficult to manipulate. In this talk I will discuss the importance of the CRISPR/Cas9 system. I will also describe our efforts to identify Cas proteins in environmental samples in order to track evidence of genetic engineering.

Biography

James J. Davis is a computational biologist and staff scientist at Argonne National Laboratory and the University of Chicago. He earned his Ph.D. in microbiology from the University of Illinois at Urbana Champaign and did his postdoctoral work under the direction of Carl R. Woese at the University of Illinois Carl R. Woese Institute for Genomic Biology.  He joined Argonne in 2013, where he has been doing research in comparative genomics, antibiotic resistance, genome annotation, phylogeny and algorithm design. Davis is involved in maintaining the RAST annotation system and SEED and PATRIC databases, which have over 20,000 users. He has been instrumental in several key projects for these resources including designing algorithms for the RAST tool kit and building protein families that can scale to over 100,000 genomes in the PATRIC database. Davis also has a publication record designing machine learning studies for predicting antimicrobial resistance from genome sequence data.