לוח שנה משולב

Social animals have to know the spatial positions of conspecifics. However, it is unknown how the position of others is represented in the brain. We designed a spatial observational-learning task, in which an observer bat mimicked a demonstrator bat while we recorded hippocampal dorsal-CA1 neurons from the observer bat. A neuronal subpopulation represented the position of the other bat, in allocentric coordinates. About half of these “social place cells” represented also the observer’s own position—that is, were place cells. The representation of the demonstrator bat did not reflect self-movement or trajectory planning by the observer. Some neurons represented also the position of inanimate moving objects; however, their representation differed from the representation of the demonstrator bat. This suggests a role for hippocampal CA1 neurons in social-spatial cognition.

Within the last decade solid-state NMR has grown as a powerful tool ‎in structural biology. This talk will focus on studies of protein ‎dynamics with the use of deuteron NMR under static conditions and ‎over a very broad temperature range. We will discuss experimental ‎and computational methodologies that enabled detailed ‎characterization of side-chain dynamics in hydrophobic cores of ‎globular proteins as well as in amyloid fibrils of various ‎morphologies. Finally, we will present preliminary results pertaining ‎to disordered regions of amyloid-beta.‎

The celebrated KPZ equation (Kardar, Parisi, Zhang, 1986) is an important milestone in statistical physics, originally introduced to describe the late time dynamics in two dimensional growth models. Over the last 30 years, the KPZ story has evolved in various interesting directions, making links on the way to different areas of physics and mathematics. This includes in particular the link to the famous Tracy-Widom distribution in random matrix theory. The story of KPZ is a very successful one, involving theoretical physics, mathematics and experiments--a fertile playground for interdisciplinary science. In this talk, I will review the evolution of the KPZ story, pointing out the important landmarks as I go along. At the very end, I will discuss some recent developments establishing a nice link between the KPZ height fluctuations and the edge physics in cold atom systems.

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western world. The disease is characterized by decreased apoptosis and accumulation of mature B lymphocytes. We have previously shown that CD74 induces a downstream cascade that regulates CLL survival. Recently, we showed that CD74-intracellular domain interacts with the transcription factors RUNX and NF-B and binds to proximal and distal regulatory sites enriched for genes involved in apoptosis, immune response and cell migration. One of CD74 target genes is CD84. Our results demonstrate that CD84 mediates the interaction of CLL cells with their microenvironment inducing cell survival. In addition, activation of CD84 elevates PD-L1 expression on CLL cells and their microenvironment which interact with PD-1 expressed on T cells. Our results suggest CD84 blockade as a novel therapeutic strategy to reverse tumor-induced immune suppression.

The governing role of hydrophobic interactions in countless biological phenomena and technological systems, including protein folding, transmembrane proteins, cell membranes, detergents, paints, decontamination of pollute water, and more, has motivated extensive theoretical and experimental efforts aimed at deciphering the microscopic foundations of this interaction. Yet, after more than a century of extensive research a full predictive theory of this elusive phenomenon is still missing, largely due to the lack of suitable experimental techniques capable of probing the interface between hydrophobic surfaces and water at high enough resolution. In the talk, I will present our recent explorations of this interface using an ultra-high resolution atomic force microscope built in-house for the task and disclose compelling evidence that the hydrophobic interaction reflects a phase transition taking place in the medium when two hydrophobic surfaces approach each other to within a few nanometers. Along the way I'll demonstrate the sub-atomic resolution of our microscope and its value for the study of water structure near surfaces and biomolecules.