| | Astronomy: A black hole changes its feeding habits
In the 1980s, the gas surrounding a black hole in a nearby galaxy began to emit much more radiation than before. This change has unexpectedly reversed in the past five years, questioning our understanding of these extreme phenomena.
| Biological rhythms: Wild times
Little is known about the biological rhythms that emerge from social behaviours in the wild. A study of shorebird pairs shows that rhythms of nest-incubation duties are mainly governed by strategies to avoid predators.
| Cell biology: Double agents for mitochondrial division
Mitochondrial organelles — the energy powerhouses of the cell — must divide and fuse dynamically to function. It emerges that two distinct dynamin enzymes enable mitochondrial division.
| The genomic basis of circadian and circalunar timing adaptations in a midge
Genomic and molecular analyses of Clunio marinus timing strains suggest that modulation of alternative splicing of Ca2+/calmodulin-dependent kinase II represents a mechanism for evolutionary adaptation of circadian timing.
| Redefining the invertebrate RNA virosphere
Profiling the total RNA of 220 invertebrate species leads to the discovery of almost 1,500 new species of RNA virus, revealing that the RNA virosphere is much more diverse than was previously thought.
| Sub-ice-shelf sediments record history of twentieth-century retreat of Pine Island Glacier
Many glaciers and ice shelves in the West Antarctic Ice Sheet are retreating or thinning rapidly, but the triggering mechanism has been unclear; now, the retreat of Pine Island Glacier is found to have begun in the 1940s following warming El Niño events in the Pacific Ocean, showing that glacial retreat can continue long after an initial push from the climate.
| Water balance creates a threshold in soil pH at the global scale
There is an abrupt transition from alkaline to acid soil pH when mean annual precipitation exceeds mean annual potential evapotranspiration, demonstrating that climate creates a nonlinear pattern in soil solution chemistry at the global scale.
| Structure of photosystem II and substrate binding at room temperature
The structures of three intermediate states of photosystem II, which is crucial for photosynthesis, have been solved at room temperature, shedding new light on this process.
| Unexpected diversity in socially synchronized rhythms of shorebirds
Socially synchronized rhythms in shorebirds were assessed during biparental incubation under natural circumstances and were exceptionally diverse, often not following the 24-h day, whereby risk of predation, not starvation, determined some of the variation in incubation rhythms.
| Inhibition of mTOR induces a paused pluripotent state
Inhibition of mechanistic target of rapamycin (mTOR) suspends mouse blastocyst development and the cells remain 'paused' in a reversible pluripotent state, allowing prolonged culture.
| Synthetic recording and in situ readout of lineage information in single cells
| Corrigendum: The Asian monsoon over the past 640,000 years and ice age terminations
| | | Brief Communications Arising | | | | Emergent phenomena induced by spin–orbit coupling at surfaces and interfaces
The interplay between spin–orbit coupling and two-dimensionality has led to the emergence of new phases of matter, such as spin-polarized surface states in topological insulators, interfacial chiral spin interactions, and magnetic skyrmions in thin films, with great potential for spin-based devices.
Anjan Soumyanarayanan, Nicolas Reyren, Albert Fert et al. | | The mechanism of force transmission at bacterial focal adhesion complexes
The mystery of how bacteria that lack motile structures such as pili or flagella can 'glide' along surfaces is solved by a detailed description of the bacterial focal adhesion complex and its associated protein machinery.
Laura M. Faure, Jean-Bernard Fiche, Leon Espinosa et al. | Developmental mechanisms of stripe patterns in rodents
Alx3-induced modulation of Mitf expression alters melanocyte differentiation and gives rise to the hair colour differences underlying the repeated evolution of dorsal stripes in rodents.
Ricardo Mallarino, Corneliu Henegar, Mercedes Mirasierra et al. | Bacteria establish an aqueous living space in plants crucial for virulence
A combination of high humidity and bacterial effectors, such as Pseudomonas syringae HopM1, creates an aqueous environment in the apoplast of immunodeficient Arabidopsis thaliana that allows non-pathogenic P. syringae strains to become virulent pathogens.
Xiu-Fang Xin, Kinya Nomura, Kyaw Aung et al. | | Doped polymer semiconductors with ultrahigh and ultralow work functions for ohmic contacts
A general strategy for producing solution-processed doped polymers with the extreme work functions that are required to make good ohmic contacts to semiconductors is demonstrated in high-performance light-emitting diodes, transistors and solar cells.
Cindy G. Tang, Mervin C. Y. Ang, Kim-Kian Choo et al. | The evolving quality of frictional contact with graphene
Atomistic simulations reproduce experimental observations of transient frictional strengthening of graphene on an amorphous silicon substrate, an effect which diminishes as the number of graphene layers increases.
Suzhi Li, Qunyang Li, Robert W. Carpick et al. | Catalytic activation of carbon–carbon bonds in cyclopentanones
In the chemical industry, it is often necessary to activate carbon–carbon bonds in order to synthesize complex organic molecules, but this is challenging when starting with simple five- or six-membered carbon rings; a new method uses a rhodium pre-catalyst and an amino-pyridine co-catalyst, enabling an overall energetically favourable reaction that involves activation of carbon–carbon bonds plus activation of carbon–hydrogen bonds.
Ying Xia, Gang Lu, Peng Liu et al. | Magnetic reversals from planetary dynamo waves
Polarity reversals caused by dynamo waves are demonstrated in a magnetohydrodynamic model that is relevant to planetary cores, suggesting a possible mechanism of geomagnetic reversals.
Andrey Sheyko, Christopher C. Finlay, Andrew Jackson | A cannabinoid link between mitochondria and memory
Cannabinoids affect CB1 receptors on the mitochondrial membranes in the brain, triggering a decrease in downstream cAMP-dependent signalling; this leads to a decrease in brain mitochondrial activity and to cannabinoid-induced amnesia.
Etienne Hebert-Chatelain, Tifany Desprez, Román Serrat et al. | Designer matrices for intestinal stem cell and organoid culture
The authors have designed modular synthetic hydrogel networks for mouse and human intestinal stem cell cultures that support intestinal organoid formation.
Nikolce Gjorevski, Norman Sachs, Andrea Manfrin et al. | Different tissue phagocytes sample apoptotic cells to direct distinct homeostasis programs
Apoptotic intestinal epithelial cells can be sampled by lamina propria phagocytes, leading to distinct phagocyte-type-specific anti-inflammatory gene signatures and dendritic-cell-mediated induction of regulatory T cells.
Ryan J. Cummings, Gaetan Barbet, Gerold Bongers et al. | Macrophages redirect phagocytosis by non-professional phagocytes and influence inflammation
Macrophage-derived insulin-like growth factor enhances the uptake of microvesicles by non-professional phagocytes, such as airway epithelial cells and fibroblasts, thereby dampening tissue inflammation.
Claudia Z. Han, Ignacio J. Juncadella, Jason M. Kinchen et al. | Control of mitochondrial function and cell growth by the atypical cadherin Fat1
Fragments of the atypical cadherin Fat1 accumulate in the mitochondria of vascular smooth muscle cells where they reduce respiration, leading to a regulated proliferative response to arterial injury.
Longyue L. Cao, Dario F. Riascos-Bernal, Prameladevi Chinnasamy et al. | Mechanism of super-assembly of respiratory complexes III and IV
SCAF1 is always required for the interaction between the respiratory chain complexes III and IV, and in animals carrying only the short isoform of SCAF1, the respirasome is absent in most tissues, with the exception of heart and skeletal muscle, where COX7A2 is present instead of SCAF1.
Sara Cogliati, Enrique Calvo, Marta Loureiro et al. | Cascading MutS and MutL sliding clamps control DNA diffusion to activate mismatch repair
MutS and MutL—the highly conserved core proteins responsible for the repair of mismatched DNA—form sequential stable sliding clamps that together modulate one-dimensional diffusion along the DNA and, with MutH, facilitate the search for a distant excision initiation site.
Jiaquan Liu, Jeungphill Hanne, Brooke M. Britton et al. | Genetic and mechanistic diversity of piRNA 3′-end formation
Drosophila have two pathways for PIWI-interacting RNA (piRNA) 3′-end formation—depending on which pathway is used, piRNA biogenesis is directed towards either cytoplasmic or nuclear PIWI protein effectors, which balances post-transcriptional versus transcriptional transposon silencing.
Rippei Hayashi, Jakob Schnabl, Dominik Handler et al. | An oxidative N-demethylase reveals PAS transition from ubiquitous sensor to enzyme
Characterization of the first Per-ARNT-Sim enzyme, a haem-dependent oxidative N-demethylase.
Mary Ortmayer, Pierre Lafite, Binuraj R. K. Menon et al. | | | | |
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