לוח שנה משולב

The Covid-19 pandemic emphasized the need for antiviral drugs to block infection and spread of emerging coronaviruses (CoVs). We designed a high-content screen based on Vesicular Stomatitis pseudoviruses that lack the G glycoprotein and express instead a fluorescent reporter (VSVΔG). We used the platform to conduct a high-throughput screen of 173,227 unique small molecules for their ability to inhibit pseudoviruses bearing the SARS-CoV-2 S protein.

To identify broad-spectrum inhibitors, hits were counter screened against VSVΔG pseudoviruses bearing the unrelated G glycoprotein and subsequently classified based on their ability to inhibit infection of pseudoviruses bearing the S protein of MERS-CoV that uses a different cell-surface receptor, and the SARS-CoV-2 S protein variants, alpha, delta, and omicron. This analysis identified novel compounds that inhibit infection at sub-micromolar concentrations, and the previously identified broad spectrum inhibitor Nafamostat, validating the screening approach and paving the way to studies in vivo.

The lack of interpretability is a much-criticised feature of deep neural networks. Often, a neural network is effectively a black box. However, we have recently found a group-theoretical procedure that brings inner layer signalling into a human-readable form. We applied it to a signal processing network used in magnetic resonance spectroscopy, and found that the network spontaneously invents a bandpass filter, a notch filter, a frequency axis rescaling transformation, frequency division multiplexing, group embedding, spectral filtering regularisation, and a map from harmonic functions into Chebyshev polynomials – in ten minutes of unattended training.

Recent severe summertime weather extremes in the Northern hemisphere
extratropics such as the extraordinary 2021 North American Heatwave and
the record-breaking floods in central Europe were in part driven by
persistent circulation patterns in the tropospheric Jetstream. To what degree
such circulation patterns will modulate extreme weather risk in a warming
world is still uncertain and remains a highly debated topic in climate science.
I will present results from recent studies that investigate physics of
extraordinary extremes, future changes in weather persistence diagnosed by
a feature tracking algorithm and future risks from concurrent extremes and
associated impacts on crop production based on latest GGCMI-runs. A
special emphasis will be placed on benchmarking the skill of CMIP5 and
CMIP6 models to reproduce atmosphere dynamical mechanisms and
associated extreme weather against reanalysis data
short bio: Kai Kornhuber is an adjunct Associate Research Scientist at the
Lamont-Doherty Earth Observatory, Columbia University in New York and a
Senior Fellow on Climate Risks at the German Council on Foreign Relations.
His research is concerned with physical drivers of extreme weather and
climate events and associated societal impacts and risks under current and
future climatic conditions. He is Founding Member of the EarthNetwork on
Sustainable and Resilient Living in an Era of Increasing Disasters at
Columbia’s Climate School, Co-Chair of the Compound Events Working Group
at Risk-Kan, Steering Committee member of the HiWeather Project and a Co-
Pi of the Project PERSEVERE within the BMBF Consortium.

This talk will present our recent work on the use of arrays of Rydberg atoms to study
quantum magnetism and to generate entangled states useful for quantum metrology. We
rely on laser-cooled ensembles of up to hundred individual atoms trapped in microscopic
optical tweezer arrays. By exciting the atoms into Rydberg states, we make them interact by
the resonant dipole interaction. The system thus implements the XY spin ½ model, which
exhibits various magnetic orders depending on the ferromagnetic or antiferromagnetic
nature of the interaction. In particular, we adiabatically prepare long-range ferromagnetic
order. When the system is placed out of equilibrium, the interactions generate spin squeezing. We characterize the degree of squeezing and observe that it scales with the number of atoms.