Zhang et al. reveal that hepatic ILC1s rapidly transition from intravascular patrolling to motility arrest upon encountering infected Kupffer cells (KCs) during viremia. This behavioral switch, driven by cell intrinsic type I IFN signaling and coupled to ILC1 activation, fortifies the antiviral function of KCs to restrict systemic viral dissemination.
Conditions can get rough in the micro- and nanoworld. For example, to ensure that nutrients can still be optimally transported within cells, the minuscule transporters involved need to respond to the fluctuating environment. Physicists at Heinrich Heine University Düsseldorf (HHU) and Tel Aviv University in Israel have used model calculations to examine how this can succeed. They have now published their results—which could also be relevant for future microscopic machines—in the journal Nature Communications.
In a new study published in Nature Physics, researchers have achieved the first experimental observation of a fragile-to-strong transition in deeply supercooled water, resolving a scientific puzzle that has persisted for nearly three decades.
Water has anomalous properties when cooled below freezing without crystallization. Previous studies have tracked how water’s viscosity changes with temperature, predicting it would diverge to infinity around ~227 K (−46°C), meaning liquid water’s motion would essentially freeze.
However, this prediction conflicted with other known properties of water. As a result, scientists proposed that the viscosity trend must undergo a change at a specific low temperature—the so-called fragile-to-strong transition (FST).
Using single-molecule fluorescence microscopy, Payr et al. reveal how multiple RNA-binding proteins synergize to repress translation. One RNA-binding protein binds via facilitated diffusion, recruits other proteins with highly accelerated on rate, and gets stabilized by several co-factors. The findings highlight various mRNP assembly mechanism as key to efficient translational control.
Science has a rich tradition of physics by imagination. From the 16th century, scientists and philosophers have conjured ‘demons’ that test the limits of our strongest theories of reality.
Three stand out today: Laplace’s demon, capable of perfectly predicting the future; Loschmidt’s demon, which could reverse time and violate the second law of thermodynamics; and Maxwell’s demon, which create a working heat engine at no cost.
Though imaginary, these paradoxical beings have pushed physicists towards sharper theories. From quantum theory to thermodynamics, these demons have legacies that we still feel today.
Image: Antonio Sortino
Three thought experiments involving “demons” have haunted physics for centuries. What should we make of them today?
Lamb et al. show that the circadian clock rhythmically remodels ribosome composition in Neurospora crassa. Clock-regulated incorporation of the ribosomal protein eL31 is required for rhythmic translation and translation fidelity, linking temporal ribosome remodeling to daily changes in proteome diversity.
