@article{22693, abstract = {We study torus-equivariant algebraic K-theory of affine Schubert varieties in the perfect affine Grassmannians over Fp. We further compare it to the torus-equivariant Hochschild homology of perfect complexes, which has a geometric description in terms of global functions on certain fixed-point schemes. We prove that Fp-linearly, this comparison is an isomorphism. Our approach is quite constructive, resulting in new computations of these K-theory rings. We establish various structural results for equivariant perfect algebraic K-theory on the way; we believe these are of independent interest.}, author = {Löwit, Jakub}, issn = {1431-0643}, journal = {Documenta Mathematica}, keywords = {equivariant algebraic K-theory, perfection in positive characteristic, affine Grassmannian, affine Schubert varieties, Dennis trace map, equivariant Hochschild homology, fixed-point schemes, toric varieties}, publisher = {EMS Press}, title = {{Equivariant K-theory, affine Grassmannian and perfection}}, doi = {10.4171/dm/1064}, year = {2026}, } @phdthesis{22684, abstract = {Contact electrification (CE) is a simple yet elusive phenomenon that occurs when two materials come into contact and separate, leaving behind net electrical charge. Despite its ubiquity, the microscopic origin of CE remains unclear. In this thesis, we investigate CE from three complementary perspectives: developing a quantitative method to measure charge at the nanoscale, exploring the dynamic behavior of charge on insulating surfaces, and uncovering the role of mechanical history in forming a triboelectric series. In the first part, we establish a rigorous framework for converting qualitative Kelvin probe force microscopy (KPFM) voltage maps into quantitative charge density distributions. Using finite element method (FEM) simulations, we determine the point-spread function of the KPFM tip–sample geometry and demonstrate that the true surface charge can be reconstructed by numerical deconvolution. This procedure enables the recovery of both the magnitude and sign of charge density with high fidelity, resolving nanoscale features that are otherwise obscured. Applying the method to contact-charged SiO$_2$ surfaces, we show that existing analytical approximations, such as parallel plate or spherical models, can miscalculate charge magnitude by orders of magnitude. Our hybrid FEM/KPFM approach therefore provides a fast and general method to convert qualitative KPFM signals into quantitative charge data, enabling nanoscale charge mapping under realistic experimental conditions. In the second part, we study the temporal stability of CE-induced charges and identify the key material factors that determine whether KPFM can capture meaningful charge patterns. Through time-resolved experiments combining a custom-built transfer system with both microscopic and macroscopic measurements, we demonstrate that only the best insulators, such as SiO$_2$, preserve CE charge long enough for stationary imaging. For less conductive polymers, such as PDMS, charge decays within the duration of a single KPFM scan due to bulk conduction. Using a simple capacitor-based model, we reproduce the observed decay dynamics and confirm that the transferred charge decays characteristic to the sample's bulk conductivity. Further, we always observe homogeneous charge transfer. In the third part, we address the question: can we form a triboelectric series with identical materials? Using controlled repetitive contact experiments, we show that nominally identical materials can progressively order themselves into a triboelectric series, where surfaces with more contact history charge negatively relative to fresher ones. By constructing a minimal model based on this ``contact bias'', we replicate the evolution from random to ordered charging observed in experiments. Supporting surface analyses, including atomic force microscopy, reveal that repeated contact induces nanoscale morphological changes, suggesting a mechanism tightly coupled to mechanical strain. These results highlight the crucial role of surface history and nanoscale mechanics in dictating charge transfer, motivating further exploration of mechanisms such as mechanochemical bond cleavage and flexoelectric polarization.}, author = {Pertl, Felix}, isbn = {978-3-99078-083-1}, issn = {2663-337X}, pages = {107}, publisher = {Institute of Science and Technology Austria}, title = {{Experimental probing of nanoscale charge features and surface morphology changes during tribocharging}}, doi = {10.15479/AT-ISTA-22684}, year = {2026}, } @article{21762, abstract = {Bacteria, like eukaryotes, use conserved cytoskeletal systems for intracellular organization. The plasmid-encoded ParMRC system forms actin-like filaments that segregate low–copy number plasmids. In multicellular cyanobacteria such as Anabaena sp., we found that a chromosomally encoded ParMR system has evolved into a cytoskeletal system named CorMR with a function in cell shape control rather than DNA segregation. Live-cell imaging, in vitro reconstitution, and cryo–electron microscopy revealed that CorM formed dynamically unstable, antiparallel double-stranded filaments that were recruited to the membrane by CorR through an amphipathic helix conserved in multicellular cyanobacteria. CorMR filaments were regulated by MinC, which excluded them from the poles and division plane. Comparative genomics indicated that the repurposing of ParMR and Min systems coevolved with cyanobacterial multicellularity, highlighting the evolutionary plasticity of cytoskeletal systems in bacteria.}, author = {Springstein, Benjamin L and Javoor, Manjunath and Megrian, Daniela and Hajdu, Roman and Hanke, Dustin M. and Zens, Bettina and Weiss, Gregor L. and Schur, Florian Km and Loose, Martin}, issn = {1095-9203}, journal = {Science}, number = {6795}, publisher = {AAAS}, title = {{Repurposing of a DNA segregation machinery into a cytoskeletal system controlling cell shape}}, doi = {10.1126/science.aea6343}, volume = {392}, year = {2026}, } @phdthesis{22744, author = {Javoor, Manjunath}, isbn = {978-3-99078-090-9 }, issn = {2663-337X}, keywords = {Actin cytoskeleton, Cell migration, cryo-electron tomography}, pages = {121}, publisher = {Institute of Science and Technology Austria }, title = {{Large-scale imaging of cellular actin networks at single filament resolution using montage cryo-electron tomography}}, doi = {10.15479/AT-ISTA-22744}, year = {2026}, } @article{22751, abstract = {The physical processes that led to the formation of billion-solar-mass black holes within the first 700 million years of cosmic time, a period known as cosmic dawn, remain a puzzle1. Several theoretical scenarios have been proposed to seed and rapidly grow black holes2,3,4, but direct observations of these mechanisms remain elusive. Here we present a source 660 million years after the Big Bang that exhibits singular properties: among the largest hydrogen Balmer breaks reported at any redshift, broad multi-peaked Hβ emission, and Balmer line absorption in several transitions. We model this source as an enshrouded black hole in which the Balmer break and absorption features are a result of extremely dense, turbulent gas forming a dust-free envelope around a supermassive black hole5,6. This source may provide evidence of an early black hole embedded in dense gas—a theoretical configuration proposed to rapidly grow black holes by super-Eddington accretion7,8. Radiation from the black hole seems to dominate almost all observed light, leaving limited room for contribution from its host galaxy. If the source merged with its brighter neighbour, it would resemble the recently discovered ‘little red dots’ with perplexing spectral energy distributions9,10,11. The redness of the black hole is due to gas, not dust12,13, and scattering, not kinematics, gives rise to the complex line shapes and luminosities—black hole masses of these sources may therefore be overestimated by orders of magnitude.}, author = {Naidu, Rohan P. and Matthee, Jorryt J and Katz, Harley and De Graaff, Anna and Oesch, Pascal A. and Smith, Aaron and Greene, Jenny E. and Brammer, Gabriel and Weibel, Andrea and Hviding, Raphael and Chisholm, John and Labbé, Ivo and Simcoe, Robert A. and Witten, Callum and Sun, Wendy Q. and Atek, Hakim and Baggen, Josephine F.W. and Belli, Sirio and Bezanson, Rachel and Boogaard, Leindert A. and Bose, Sownak and Bouwens, Rychard J. and Covelo-Paz, Alba and Dayal, Pratika and Fudamoto, Yoshinobu and Furtak, Lukas J. and Giovinazzo, Emma and Goulding, Andy and Gronke, Max and Heintz, Kasper E. and Hirschmann, Michaela and Illingworth, Garth and Inoue, Akio K. and Johnson, Benjamin D. and Leja, Joel and Leonova, Ecaterina and Mcconachie, Ian and Maseda, Michael V. and Natarajan, Priyamvada and Nelson, Erica and Setton, David J. and Shivaei, Irene and Sobral, David and Stefanon, Mauro and Tacchella, Sandro and Toft, Sune and Torralba Torregrosa, Alberto and Van Dokkum, Pieter and Van Der Wel, Arjen and Volonteri, Marta and Walter, Fabian and Wang, Bingjie and Watson, Darach and Whitaker, Katherine}, issn = {1476-4687}, journal = {Nature}, number = {8127}, pages = {329--333}, publisher = {Springer Nature}, title = {{A gas-enshrouded and gas-reddened black hole at cosmic dawn}}, doi = {10.1038/s41586-026-10846-4}, volume = {656}, year = {2026}, } @article{22750, abstract = {Robust oxygenic photosynthesis requires the efficient assembly and repair of the multi-subunit oxygen-evolving photosystem II (PSII) complex. Previous cryogenic electron microscopy (cryo-EM) structures of PSII assembly/disassembly intermediates have relied on the analysis of deletion mutants or removal of PSII subunits in vitro. Here we report the cryo-EM structures of naturally occurring dimeric PSII intermediates from the cyanobacterium Thermosynechococcus vestitus at a resolution of about 2.2 Å. These intermediates contain inactive dimers lacking the oxygen-evolving complex (OEC) and semi-active dimers with the OEC present in one of the two monomers. Our structural data provide a mechanism for how assembly and disassembly of the Mn4CaO5 cluster is coordinated with the binding and release of the extrinsic proteins: restructuring of the C-terminal tail of D1 subunit during assembly or disassembly of the Mn cluster triggers conformational changes in D2, CP47 and CP43 to drive the binding/release of the extrinsic proteins. A combination of structural and mass spectrometry data also suggests that the inactive PSII complexes may include damaged complexes containing oxidized D1-His332, a monodentate ligand to one of the Mn ions of the OEC.}, author = {Zhao, Ziyu and Vercellino, Irene and Whitelegge, Julian P. and Maghlaoui, Karim and Białek, Wojciech and Nixon, Peter J. and Sazanov, Leonid A}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Cryo-EM structures of naturally occurring dimeric photosystem II complexes lacking the Mn4CaO5 cluster}}, doi = {10.1038/s41467-026-75324-x}, volume = {17}, year = {2026}, } @article{22752, abstract = {In this note we outline a new and simple approach to proving central limit theorems for various ‘global’ graph parameters that have robust ‘local’ approximations, using the Efron–Stein inequality, which relies on a combinatorial analysis of the stability of these approximations under resampling an edge. As an application, we give short proofs of a central limit theorem for the order of the giant component and of the 𝑘 -core for sparse random graphs.}, author = {Anastos, Michael and Erde, Joshua and Kang, Mihyun and Pfenninger, Vincent}, issn = {1469-2120}, journal = {Bulletin of the London Mathematical Society}, number = {8}, publisher = {Wiley}, title = {{A short proof of a central limit theorem for the order of the giant component and k-core}}, doi = {10.1112/blms.70464}, volume = {58}, year = {2026}, } @phdthesis{22664, abstract = {The widespread adoption of apps like Whatsapp and Signal has translated into billions of people all around the world communicating on a regular basis by making use of services that offer end-to-end encryption and even provide security guarantees when a user's device is compromised. This was made possible by the introduction of the Double Ratchet Algorithm~\cite{double_ratchet}, which was designed for a setting where communication takes place between two parties. However, in practice, many apps offer the possibility of creating groups. The protocols they use to secure communication are inefficient for large group which has the undesireable consequence that the aforementioned apps have established limits on the group size of roughly 1000 users. This has motivated the introduction of the Messaging Layer Security (MLS) standard~\cite{rfc9420} by the IETF which is based on a primitive called Continuous Group Key Agreement (CGKA)~\cite{C:ACDT20}. This primitive allows a group of users to maintain a shared secret key that is frequently rotated by the group members in order to change group membership, achieve forward secrecy (FS) and post compromise security (PCS). Most protocols are based on binary trees where the nodes are associated to a pair formed by public key and a secret key. Each leaf corresponds to one of the group members and a user knows the secret keys associated to nodes along the path from their leaf to the root. When a user wants to update their key material they have to change $ \log(N) $ many keys. This requires uploading $ \log(N) $ many ciphertexts to communicate the new keys to the rest of the group members in a way that respects the tree structure. In this thesis we study how much communication between group members is required in order to add and remove users from a group as well as in order to provide PCS when we consider CGKAs built using standard cryptographic primitives like pseudo-random functions and public-key encryption. Furthermore, we also consider the case of MLS and provide the first lower bound showing that its communication complexity is much worse than previously believed, i.e., it is very far from $ \log(N) $. Finally, we also propose a variant of MLS which provably achieves the same security properties with a much lower communication cost.}, author = {Cueto Noval, Miguel}, isbn = { 978-3-99078-087-9}, issn = {2663-337X}, pages = {187}, publisher = {Institute of Science and Technology Austria}, title = {{Towards efficient secure group messaging}}, doi = {10.15479/AT-ISTA-22664}, year = {2026}, } @inproceedings{22754, abstract = {Quantitative automata (QAs) extend finite-state automata on infinite words with weighted transitions to specify quantitative system properties. However, their finite weight sets rule out properties like average response time, where response times can be arbitrarily large. Nested quantitative automata (NQAs) overcome this limitation: a parent automaton spawns child automata to compute unbounded values over finite infixes and aggregates them into a final result. Despite this expressiveness, NQAs have lacked practical tool support to date. We close this gap by extending the Quantitative Automata Kit (QuAK), a software tool for QA analysis, to support NQAs. Our core contribution is implementing a suite of flattening procedures that reduce NQAs to QAs, leveraging QuAK’s existing decision procedures. These reductions preserve the answers to threshold decision problems, while allowing users to specify properties in the more expressive NQA formalism. The tool handles all combinations of parent aggregators (including limits and averages) and child functions (extrema and monotonic or bounded summations) for which emptiness and universality are known to be decidable. Experiments on response-time and resource-consumption benchmarks demonstrate QuAK’s effectiveness.}, author = {Henzinger, Thomas A and Mazzocchi, Nicolas Adrien and Sarac, Naci E and Yılmaz, Harun}, booktitle = {38th International Conference on Computer Aided Verification}, isbn = {9783032325259}, issn = {1611-3349}, location = {Lisbon, Portugal}, pages = {418--432}, publisher = {Springer Nature}, title = {{Extending QuAK with nested quantitative automata}}, doi = {10.1007/978-3-032-32526-6_20}, volume = {16683}, year = {2026}, } @article{22755, abstract = {The eigenstate thermalization hypothesis (ETH) posits how isolated quantum many-body systems thermalize, assuming that individual eigenstates at the same energy density have identical expectation values of local observables in the limit of large systems. While the ETH apparently holds across a wide range of interacting quantum systems, in this work, we show that it may require generalization in the presence of thermal first-order phase transitions. We introduce a class of all-to-all spin models, featuring first-order thermal phase transitions that stem from two distinct local maxima of entropy (two mean-field solutions that we dub “branches”) that exchange dominance in the many-body density of states as the energy is varied. We argue that, for energies in the vicinity of the thermal phase transition, eigenstate expectation values do not need to converge to the same thermal value. The system has a regime with coexistence of two classes of eigenstates corresponding to the two branches with distinct expectation values at the same energy density and another regime with Schrödinger-cat-like eigenstates that are interbranch superpositions; these two regimes are separated by an eigenstate phase transition. We propose a more general form of the ETH , support our results by semiclassical calculations and an exact diagonalization study of a microscopic spin model, and argue that the structure of eigenstates in the vicinity of thermal first-order phase transitions can be experimentally probed via nonequilibrium dynamics.}, author = {Serbyn, Maksym and Avdoshkin, Alexander and Diessel, Oriana K. and Huse, David A.}, issn = {2160-3308}, journal = {Physical Review X}, number = {3}, publisher = {American Physical Society}, title = {{Eigenstate thermalization in thermal first-order phase transitions}}, doi = {10.1103/4zs8-7kf4}, volume = {16}, year = {2026}, } @article{22753, abstract = {Radial glial progenitors (RGPs) produce all excitatory neurons in the developing cerebral cortex. Mosaic analysis with double markers (MADM)-based lineage tracing in vivo has revealed a quantitative framework of RGP lineage progression1. Here we established MADM technology2,3 in mouse embryonic stem cells to probe RGP lineage progression in a self-organizing cortical organoid system. We found that RGPs exhibit a high level of plasticity in proliferative potential in organoids rather than strict temporally stereotyped lineage progression as observed in vivo. RGPs in organoids showed increased lineage restriction, diminishing cell-type diversity in clones of cortical projection neurons, despite uniform single-cell transcriptional signatures of RGPs and a unitary lineage trajectory. Thus, critical non-cell-autonomous cues that are absent in self-organizing systems and/or the genuine stem cell niche are essential for faithful temporal control of RGP lineage progression and the generation of clonal cortical cell-type diversity.}, author = {Stouffer, Melissa A and Miranda, Osvaldo and Pauler, Florian and Pipicelli, Fabrizia and Streicher, Carmen and Cheung, Giselle T and Hippenmeyer, Simon}, issn = {1476-4687}, journal = {Nature}, publisher = {Springer Nature}, title = {{Temporal uncoupling of radial glia lineage progression in cortical organoids}}, doi = {10.1038/s41586-026-10916-7}, year = {2026}, } @article{22381, abstract = {Context. X-ray binaries exhibit complex variability patterns studied in the power spectrum. These include the broadband noise (BBN) components and various types of narrow components called quasi-periodic oscillations (QPOs). There is currently no consensus about what determines the presence or absence of the BBN or what generates the QPOs. Many believe that QPO generation is due to framedragging effects caused by Lense–Thirring torques. Aims. We investigated the potential impact of frame-dragging effects on the accretion disk itself. In particular, we focused on its impact on the observed variability and on the presence (and types) of associated QPOs. Methods. We made analytical estimates to assess the potential presence of a geometric warp in the inner accretion disk during state transitions. Results. We show that the presence of a warp can modify the spectral-timing properties in a way that matches the observed transition between QPO types during outbursts. We also discuss the peculiar case of Cyg X-1, as well as how the hard-to-soft transition could be driven by the warp itself. Conclusions. The (expected) emergence of a warp provides a consistent explanation for the evolution of both the BBN and the QPO properties during state transitions. This offers a first path toward unifying the variability of black hole X-ray binaries.}, author = {Marcel, G. and Turner, S. G. D. and Ricketts, B. J. and López-Barquero, V. and Buisson, D. J. K. and Vincentelli, F. and Middleton, M. and Reynolds, C.S. and Avara, Mark}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{Disk warping and black hole X-ray binaries: I. Tentative unification of low-frequency quasi-periodic oscillations}}, doi = {10.1051/0004-6361/202558103}, volume = {710}, year = {2026}, } @article{22771, abstract = {Elucidating reaction mechanisms requires efficient generation of transition states (TSs) and products. Existing diffusion and sequence-based models accelerate parts of this process over traditional string-based methods, but typically still require manual enumeration of either TSs or products, and stochastic diffusion dynamics can be inefficient and hard to control. We introduce MolGEN, a conditional flow-matching framework that uses deterministic optimal transport to map Gaussian priors to chemical distributions. For TS generation, MolGEN improves TS geometry and barrier-height prediction over diffusion models while enabling sub-second sampling. For reaction product generation, it achieves competitive top-k accuracy while preserving mass and electron balance. Using the same backbone for TS and product sampling, MolGEN enables template-free generative exploration of reaction networks without the repeated quantum-chemistry searches required by prior methods. For the γ-ketohydroperoxide decomposition network, it produces more valid TSs than string-based methods using only 12 quantum-chemistry evaluations instead of 1156, and identifies a lower-barrier pathway.}, author = {Tuo, Ping and Chen, Jiale and Li, Ju}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Flow matching for reaction pathway generation}}, doi = {10.1038/s41467-026-75654-w}, volume = {17}, year = {2026}, } @misc{22852, abstract = {This Research Data contains supplemental videos for Chapter 4 "Designing bistable nanostructures for target behavior" of my PhD Thesis "Biological functionality without biochemistry: designing nanomachines for target behavior". Supplemental video 1: Video showing the transition pathway of a bistable nanostructure with sphere-based arms, corresponding to the Machine in Scenario 4. Supplemental video 2: Video showing the transition pathway of the Source in Scenario 1. The arm tips change sides during the transition, demonstrating that the arms pass through each other. Supplemental video 3: Video showing the transition pathway of a fully polyhedral hinge structure with unconstrained arms. Note that we only show the ends of the arms. Supplemental video 4: Video showing the transition pathway of the coupled energy-delivery reaction of a Machine (gray) and a Source (blue) nanostructure for the optimized parameters in Scenario 3. Note that we only show the ends of the arms.}, author = {Ehrmann, Andreas}, keywords = {functional nanostructures, bistability, target behavior, transition pathway}, publisher = {Institute of Science and Technology Austria}, title = {{Supplemental videos for Designing bistable nanostructures for target behavior}}, doi = {10.15479/AT-ISTA-22852}, year = {2026}, } @article{22769, abstract = {Using transition metals efficiently in aqueous batteries requires transferring multiple electrons per metal, which leads to difficult-to-manage conversion reactions. It is now shown how vanadium can be changed from one-electron insertion to four-electron conversion.}, author = {Freunberger, Stefan Alexander}, issn = {1476-4660}, journal = {Nature Materials}, number = {9}, pages = {1482--1483}, publisher = {Springer Nature}, title = {{Triggering conversion in vanadium electrodes}}, doi = {10.1038/s41563-026-02714-3}, volume = {25}, year = {2026}, } @article{22773, abstract = {An important quantity in liquid state theory is the radial distribution function g(r). It can be calculated within the framework of classical density functional theory in two very distinct ways. In the test-particle route, one fixes a single fluid particle, turning it into an external potential in which the inhomogeneous structure of the fluid is calculated by minimizing the functional. The second route to g(r) in density functional theory employs the Ornstein–Zernike equation and the pair direct correlation function, that can be obtained from the second functional derivatives of the excess (over the ideal gas) free energy functional. Since typically an approximate excess free energy functional is employed, the test-particle route, which requires only one functional derivative, is more accurate than the Ornstein–Zernike route. Here we study a two-dimensional core-shoulder particle system and find that in some circumstances the results from the Ornstein–Zernike route can be comparable in accuracy to the test-particle results for r > σ, the core diameter. We also examine in detail the asymptotic r → ∞ decay of g(r), finding a variety of possible decay wavelengths at different state points and state points where there is a crossover from one wavelength to a very different one. This behavior is a signature pointing to the rich phase behavior of the incipient solid phases.}, author = {Wassermair, Michael and Kahl, Gerhard and Archer, Andrew J. and Roth, Roland}, issn = {1520-5207}, journal = {Journal of Physical Chemistry B}, number = {33}, pages = {8514--8526}, publisher = {American Chemical Society}, title = {{Radial distribution function in a two-dimensional core-shoulder particle system}}, doi = {10.1021/acs.jpcb.6c00653}, volume = {130}, year = {2026}, } @article{22815, abstract = {The mass assembly and chemical enrichment of the first galaxies provide key insights into their star formation histories and the earliest stellar populations at cosmic dawn. Here we compile and utilise new, high-quality spectroscopic JWST/NIRSpec Prism observations from the JWST archive. In particular, we extend the wavelength coverage beyond the standard pipeline cut-off (5.3 μm) up to 5.5 μm, which enables for the first time a detailed examination of the rest-frame optical emission-line properties for galaxies at z ≈ 10. Crucially, the improved calibration allows us to detect Hβ and the [O III] λλ4959, 5007 doublet and resolve the auroral [O III] λ4363 line for the 11 galaxies in our sample (z = 9.3 − 10.0) to obtain direct Te-based metallicity measurements. We find that the interstellar medium (ISM) of all galaxies shows high ionisation fields and electron temperatures, with derived metallicities in the range 12 + log(O/H) = 7.1 − 8.3 (3–50% solar), consistent with previous strong-line diagnostics based on JWST data at high redshifts. We derive an empirical relation for MUV and 12 + log(O/H) at z ≈ 10, useful for future higher-redshift studies, and show that the sample galaxies are ‘typical’ star-forming galaxies though with relatively high specific star formation rates (median sSFR = SFRHβ/M★ = 38 Gyr−1) and with evidence of bursty star formation on 10 Myr versus 100 Myr timescales (log10(SFR10/SFR100)≈0.7). Combining the rest-frame optical line analysis and detailed UV to optical spectro-photometric modelling, we determine the mass-metallicity relation (MZR) and the fundamental metallicity relation (FMR) of the sample, pushing the previous redshift frontier of these measurements to z = 10. These results, together with literature measurements, point to a gradually decreasing MZR at higher redshifts, with a break in the FMR at z ≈ 3, decreasing to metallicities ≈3× lower at z = 10 than observed in galaxies during the majority of cosmic time at z = 0 − 3, likely caused by massive pristine gas inflows diluting the observed metal abundances during early galaxy assembly at cosmic dawn.}, author = {Pollock, Clara L. and Gottumukkala, Rashmi and Heintz, Kasper E. and Brammer, Gabriel B. and Roberts-Borsani, Guido and Oesch, Pascal A. and Witstok, Joris and Arellano-Córdova, Karla Z. and Cullen, Fergus and Scholte, Dirk and Terp, Chamilla and Rowland, Lucie and Sneppen, Albert and Ito, Kei and Valentino, Francesco and Matthee, Jorryt J and Watson, Darach and Toft, Sune}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{Novel z ∼ 10 auroral line measurements extend the gradual offset of the fundamental metallicity relation deep into the first gigayear of cosmic time}}, doi = {10.1051/0004-6361/202556032}, volume = {708}, year = {2026}, } @article{22772, abstract = {The cytoplasmic antiviral sensor MDA5 is activated by double-stranded RNAs. Endogenous double-stranded RNAs are modified by the A-to-I RNA-editing ADAR family to prevent activation of MDA5. In vivo, cytoplasmic ADAR1p150 is critically required to suppress MDA5 activation, yet the editing signature of all ADAR isoforms is strongly overlapping in mice. Further, it is not clear how A-to-I modifications in dsRNA prevent MDA5 activation. Here we show that 3′ UTRs harboring inverted repeats activate MDA5 in vitro and in cells. In vitro editing by either ADAR isoform leads to editing at overlapping hotspot regions and prevents MDA5 activation in vitro and in cells. Remarkably, only inosines introduced by RNA editing are capable of suppressing MDA5 activation, while replacing guanosines with inosines during in vitro transcription has no impact on MDA5 activation. A comparison of inosines introduced by ADAR1p150 in vitro, in cells, and in vivo suggests that a small number of A-to-I conversions may be critically required to suppress MDA5 activation. As those critical editing events are predominantly altering A:U basepairs into I:U wobble basepairs, we suggest that the helical distortion introduced by those wobble pairs may prevent MDA5 polymerization and thus downstream activation of the type I interferon response.}, author = {Varada, Rajagopal and Leuchtenberger, Alina F. and Vesely, Cornelia and Kaczmarek, Beata M and Mansouri Khosravi, Hamid and Mandl, Therese C. and Milanovic, Katarina and Honarmand Tamizkar, Kasra and Rajendra, Vinod and Senoner, Hannes and Steinbichl, Linda and Borojevic, Marija and Sombke, Andy and Schmidt, Katy and Eckhard, Margret and Hofacker, Ivo L. and Walkley, Carl and Heraud-Farlow, Jacki E. and Picardi, Ernesto and Bernecky, Carrie A and Jantsch, Michael F.}, issn = {1362-4962}, journal = {Nucleic Acids Research}, number = {16}, publisher = {Oxford University Press}, title = {{Distinguishing self from non-self RNA by editing-specific inosine patterns}}, doi = {10.1093/nar/gkag845}, volume = {54}, year = {2026}, } @article{22814, abstract = {We present a study of a pseudo little red dot with no metal lines (Pseudo-LRD-NOM), a highly magnified lowmass galaxy behind the lensing cluster A370 at z = 5.96. We classify this object as a pseudo-LRD because its red rest-frame optical color is contaminated by a prominent Hα line (with EW0 ≳ 800 Å) present in its JWST NIRSpec spectrum. Hα is dominated by a narrow component and also has a minor broad component indicative of an active black hole with MBH ≈ 5.6 × 10^6 M⊙. A narrow Hβ emission line is also detected (where the signal-tonoise ratio, S/N, is 8), producing a Balmer decrement (narrow) Hα/Hβ = 11. The rest-frame UV spectral slope is ßspec/uv = - 1.20 ± 0.28. All these features can be ascribed to high dust attenuation. However, no [O III]λ5007 or any other metal lines are detected in the spectrum, so [O III]5007/Hβ < 0.25, at odds with a simple dust attenuation explanation. Accounting for all the spectral properties requires the model of a starburst with moderate color excess E(B − V )≈0.2–0.5, high gas density (nH ≳ 10^6 cm^−3 ), and low- to extremely-low gas/stellar metallicities (Z = 0.01–0.1 Z⊙). The demagnified stellar mass is × 2.25+ 0 1 . . 8 3 3 0 10^7 M , and the stellar-mass surface density is = + * 418 M pc 310 725 2, similar to that of massive/nuclear star clusters. Pseudo-LRD-NOM provides evidence of massive black-hole growth occurring in a high-density, dusty starburst that is at the early stages of its chemical enrichment, and is likely a precursor to a real LRD.}, author = {Caputi, Karina I. and Cooper, Ryan A. and Rinaldi, Pierluigi and Navarro-Carrera, Rafael and Iani, Edoardo and Tumborang, Abigail A.}, issn = {1538-4357}, journal = {The Astrophysical Journal}, number = {2}, publisher = {IOP Publishing}, title = {{Pseudo Little Red Dot: An active black hole embedded in a dense and dusty, metal-poor starburst galaxy at z = 5.96}}, doi = {10.3847/1538-4357/ae80b9}, volume = {1007}, year = {2026}, } @article{22812, abstract = {Efficient data structures for computing the cutset of a set of nodes in a graph undergoing dynamic edge insertions/deletions are well-studied in undirected graphs. We study this problem in directed graphs and show a reduction from the Online Boolean Matrix-Vector Multiplication Conjecture (OMv) introduced by Henzinger et al. [STOC’15]. We prove conditional on OMv that a dynamic data structure computing the directed cutset of a set of nodes cannot have an amortized time of both O(n2−ε) for a query operation and O(n1−ε) for an update operation, for any constant ε > 0, even when an adversary’s operations are restricted to the incremental or decremental settings. We further give algorithms to match these lower bounds.}, author = {Hahn, Niklas and Henzinger, Monika H and Stefankovic, Zofia}, issn = {0020-0190}, journal = {Information Processing Letters}, keywords = {Dynamic algorithms, Graph algorithms, Directed graphs, Lower bounds, Upper bounds}, publisher = {Elsevier}, title = {{Tight bounds on the performance of dynamic directed cutset data structures based on OMv}}, doi = {10.1016/j.ipl.2026.106663}, volume = {195}, year = {2026}, }