Integrated Calendar

The olfactory bulb is the only recipient of direct olfactory sensory input in the brain and is therefore considered indispensable for odor detection. However, some humans demonstrate normal olfaction despite OB absence. The mechanisms involved in preserving olfaction and the pathogenesis leading to this condition are unknown. We use a mouse model mimicking vascular injury typical of the premature brain. We mapped maturation of blood vessels during development and found selective vulnerability of olfactory bulb vasculature during a specific developmental stage. This injury led to the development of adult, healthy mice with 5% - 35% of the original OB size. Mice could perform innate and learned olfactory tasks, and odor-specific sniff-locked responses were recorded from Piriform cortex. Anatomically, olfactory sensory neurons connect to the rudimentary OB and other ectopic regions and lose typical glomerular convergence. Accordingly, mitral/tufted apical dendrite extends beyond the territory of a single glomerulus. These and additional anatomical findings present alternative nose-to-brain connectivity may underlie preservation of olfaction in humans with degenerated olfactory bulbs.

What is the fastest way to heat a system? A naive approach that we commonly use in our kitchen is to put the system in the hottest oven available. Somewhat counter-intuitively, this naive approach is not always optimal: for some systems a pre-cooling stage can significantly accelerate the heating. Such non-monotonic optimal heating protocols are one type of anomalous thermal relaxations. In this talk I will discuss several types of anomalous thermal relaxations, give some intuition for their existence, explain how to find them in large, many body systems and present some recent results on anomalous relaxations through a second order phase transition.

7T MRI has proven itself as a great tool for neuroscientific investigation and has been embraced by many researchers for both structural and functional neuroimaging. This talk will focus on acquisition for functional MRI at UHF. Gradient-echo BOLD fMRI is a long- and well-established tool for mapping brain activation in general neuroscience applications, owing to its robustness, acquisition speed and high sensitivity. With the signal change being driven by local deoxyhemoglobin content as a composite effect of the blood flow (CBF), blood volume (CBV) and oxygen uptake (CMRO2) response to neuronal activation, there is an overall weighting towards the draining vasculature as we go up in field strength. The super-linear sensitivity gains with B0 thus come at the expense of specificity, and this makes alternative measures such CBV or CBF more attractive, especially when aiming to resolve activation to laminar or columnar details with submillimetre resolutions. Making these techniques routinely useful, however, poses new acquisition-methodological challenges. In this talk I will discuss some of the advances in non-BOLD and non-echo-planar fMRI acquisition, with some focus on lifting the coverage limitations of VASO fMRI and CBF/ASL with parallel imaging, as well as non-Cartesian approaches to CBV and CBF measurement. Finally, I will touch on the topic of parallel RF transmission which undoubtedly play a role in future methodology and once more operator- and researcher-friendly implementations are available

https://weizmann.zoom.us/j/97641167767?pwd=YURCbjI5VjdJZ2hmWXAwMTVCS1p3UT09

Nearly 100 years ago, Jones and Dole experimentally pointed out a puzzle associated with the incremental modification of the bulk viscosity of water induced by small concentrations of salt. The strange behavior relates to cation specificity. This puzzle remains unsolved. This talk will remind you about this problem and suggest a possible approach. I hope that I can engender some ideas from you.

Chemical coupling plays the essential role in metabolism of providing a mechanism by which energy released in an exergonic chemical reaction (often ATP hydrolysis) can be used to drive a different reaction energetically uphill. Through evolution coupling has come to be used also to drive the creation of concentration gradients across membranes via membrane molecular pumps such as the Na+K+ ATPase, and to harness chemical energy to perform mechanical work via proteins known as molecular motors, the most paradigmatic of which is muscle, i.e. myosin moving along actin. Recent work on synthetic molecular machines has reinvigorated efforts, both experimental and theoretical, to better understand chemical coupling. The key idea involves a mechanism known as a Brownian motor where energy is used, not to cause forward motion but to prevent backward motion. These ratchet mechanisms, named after “Feynman’s ratchet”, and mathematically described by a non-equilibrium equality for a pumped chemical potential difference, have provided the intellectual basis for the design of synthetic molecular machines. Detailed investigations of these synthetic devices have provided several surprises regarding the mechanism by which external energy drives molecular machines, most especially highlighting the key role of kinetic asymmetry.