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This Week’s Discoveries | 15 March 2016

15 March 2016
This Week's Discoveries
Gorlaeus Laboratories
Einsteinweg 55
2333 CC Leiden

First Lecture

Title: Galaxy clusters at the lowest frequencies
Speaker Francesco de Gasperin (Leiden Observatory)

Francesco is a VENI fellow at the Leiden Observatory. His research is mainly based on developing and exploiting new technologies in radio-astronomy to study active galactic nuclei (AGN), galaxy clusters, galaxies and ultimately everything which emits radio waves. Abstract During the last decade, low-frequency (<1 GHz) radio-astronomy has risen from a challenging technical experiment to a productive field of observational astronomy. In particular, the Low Frequency Array (LOFAR) will provide a transformational new view on diffuse vary large scale (~Mpc) radio emission in galaxy clusters. These radio sources are the ultimate observational evidence that cluster mergers produce large scale turbulence and shocks, accelerating cosmic rays. In this talk I will present the latest results on the study of galaxy clusters at the lowest frequencies. I will focus the discussion on a new type of radio source which might become a prominent population in low-frequency deep observations of galaxy clusters: radio phoenixes. Radio phoenixes are old plasma bubbles ejected by accreting supermassive black holes and subsequently compressed/re-energized by merger-driven shocks.

Second Lecture, Lorentz Center highlight

Title: Peeling the lid on living circuits​
Speaker Klaus Hahn ( Chapel Hill, USA)

Klaus is Thurman Distinguished Professor of Pharmacology at the University of North Carolina, Chapel Hill. His lab focuses on two synergistic areas: development of proteins and small molecules to visualize and control protein activity in live cells and animals, and applying these tools to address basic questions re spatiotemporal control of signaling.
“Our biological studies center on the role of cytoskeletal and adhesion dynamics in signaling crosstalk, directed motility, and immune cell function. We are extending our cell biology studies to examine metastasis and macrophage motility in 3D models and in vivo. While addressing specific molecules for our biological studies, we have produced generally applicable approaches to visualize and control signaling. These include new fluorescent biosensor designs to quantify conformational changes of endogenous proteins, and biosensors based on engineered protein scaffolds for otherwise inaccessible molecules. We are developing fluorescent dyes for single molecule microscopy of protein conformational changes in vivo, and engineered domains that can be inserted into target proteins to control protein function using either light or small molecules. Other new methods selectively activate specific protein behaviors. We greatly benefit from interactions with collaborators who focus on computational image analysis, modeling of signaling dynamics, and developing novel microscopes”.
Klaus is participating in the Lorentz Center workshop: Optogenetics: From molecules to applications that is being held from 14 March 2016 through 18 March 2016.

Cells are comprised of a beautiful and intricate network of constantly changing components – they sense the extracellular world, integrate inputs, and decide how to proceed with thousands of specialized cell behaviors. The cellular decision making circuitry is not static – part of the logic of decision making is the constant turnover and assembly of specialized machines and logic circuits. Until recently it has not been possible to understand how such brief and localized events control cellular behavior, but now we can see individual components in the living cell, have them emit light to report their behavior, and can even control the decision-making molecules with light. This talk will briefly introduce some of the new tools enabling us to visualize and control cellular decision making, and highlight our observations of how these events control cell behavior.