LDRD seminar: July 10
Three Argonne researchers will discuss their Laboratory-Directed Research and Development (LDRD) sponsored work at the LDRD Seminar Series presentation Tuesday, July 10, 2018, at 12:30 p.m. in the Building 203 Auditorium. All are welcome to attend.
Visit the LDRD website to view upcoming seminars.
“The Electron-Ion Collider,” by Physicist Jose Repond (PSE)
The Electron-Ion Collider (EIC) was identified in the 2015 Long Range Plan for Nuclear Science as the highest priority for a new facility construction, with the mapping of the gluon content of nucleons and nuclei as the central goal. The EIC will collide electrons in the energy range of 5 to 15 GeV with protons (up to 250 GeV) or ions (up to 100 GeV per nucleon). The projected luminosity will be of the order of 1034 cm-2s-1 with both electrons and hadrons polarized. Construction is to begin in 2025 with operation slated to start in 2032.
The Argonne EIC group is building a comprehensive program which will position the laboratory to play a leadership role in the EIC project. The program features four sub-tasks which are tightly intertwined: theory developments, detector simulations, detector R&D and accelerator R&D. In addition, the group is developing a concept for a multipurpose, hermetic detector, based on the most advanced technologies currently available.
After a brief introduction into the EIC, I will review the ongoing efforts within the four sub-tasks and provide details concerning our detector concept.
“Surfing the Standing Wave to Explore Nanoscale Structures,” by Physicist Volker Rose (XSD)
Standing waves are the result of the superposition of two waves with the same amplitude and frequency traveling in opposite directions. Generally, they can be set up when a wave reflects back from a surface and the reflected wave interferes with the primary wave. At the Advanced Photon Source, such standing waves have now opened up a new view into the nano world. Combined with the emerging technique of synchrotron X-ray scanning tunneling microscopy (SX-STM), a theoretical and experimental framework has been developed to use X-ray standing waves for the localized study of surface and sub-surface structure with chemical and magnetic sensitivity.
Volker Rose is a physicist with the X-ray Science Division and Center of Nanoscale Materials as well as an Adjunct Professor at Ohio University. He holds a doctoral degree from RWTH Aachen, Germany. Rose’s research focuses on the study of nanoscale materials by means of high-resolution X-ray microscopy techniques. His research achievements include an Exemplary Business Partnership Award from Naperville Community Unit School District in 2018, a UChicago Argonne LLC Board of Governors Pinnacle of Education Award in 2015, a U.S. Department of Energy Early Career Research Program Award in 2012, and an R&D 100 Award in 2009. In 2013, he was selected to participate in the Strategic Laboratory Leadership Program of The University of Chicago Booth School of Business. Rose’s work has been covered by media outlets including The New York Times, Chicago Tribune, Discover Magazine, Voice of America and many more.
“Regulatory Network Governing Biofilm Formation at Plant-Roots,” by Microbiologist Marie-Françoise Gros (BIO)
Rhizobacteria of the Pseudomonas fluorescens group adopt a range of morphological phenotypes on the rhizoplane of Populus, ranging from micro-colonies to highly structured biofilms. Biofilm-forming bacteria have been found to be beneficial for plant growth, however, the underlying mechanisms governing the formation of biofilm at plant roots is poorly understood. In bacteria, the secondary signaling messenger cyclic diguanosine monophosphate (c-di-GMP) is a central regulator of bacterial transition from motile to biofilm life-styles. This molecule is bound by a wealth of enzymes and effector proteins that regulate specific cellular functions. The intricate interplay between all the players involved in this signaling pathways is arguably the main hindrance to our understanding of the role of c-di-GMP signaling in biofilm formation and plant growth promotion activities in this bacteria.
In cells, most proteins exert their activities in association with other proteins to form functional complexes and machineries. We combined the identification of protein complexes involved in c-di-GMP regulatory pathways with a systematic CRISPRi-based functional analysis. We built a high-quality binary protein-protein interaction (PPI) map centered on c-di-GMP signaling in P. fluorescens from very high confidence interactions. This PPI network clustered in connected functional modules, revealing functional associations connecting c-di-GMP binding proteins to particular metabolic pathways and cellular machineries relevant with plant-root interactions, such as cell signaling, transcriptional regulations, cell adhesion, and transport of various nutrients. Protein-protein networks centered onto specific signaling pathways represent a useful approach for deciphering plant-microbes interactions.
Marie-Françoise Gros is molecular microbiologist in the Biosciences division. She obtained her Ph.D. in molecular and cellular genetics at the University Paris-Orsay (France). She was research director at the National Institute for Agronomical Research (INRA) in France prior to joining Argonne in 2015. Her main interest is to understand the biological function of molecular machines in bacteria. She focuses on understanding the regulatory mechanisms underlying bacterial behavior and biofilm formation.