@article{21763, abstract = {Reactive oxygen species (ROS) have been implicated in multiple signaling processes in plants, but the underlying mechanisms and roles remain enigmatic. In this study, we developed a method of live imaging of apoplastic ROS at the root surface. Distinct signals, including auxin, extracellular adenosine triphosphate, and rapid alkalinization factor 1 peptide, induce cytosolic calcium transients and apoplastic ROS bursts. Genetic and optogenetic manipulations of Arabidopsis identified calcium transients as necessary and sufficient for ROS bursts through activation of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidases RBOHC and RBOHF. Apoplastic ROS bursts are not required, but they do limit gravity-induced root bending. Root bending is sensed by the stretch-activated calcium channel MCA1, leading to NADPH oxidase activation. The resulting ROS production stiffens cell walls to facilitate soil penetration. Apoplastic ROS thus provides a means to balance tissue flexibility and stiffness to navigate soil.}, author = {Kulich, Ivan and Vladimirtsev, Dmitrii and Randuch, Marek and Gao, Shiqiang and Citterico, Matteo and Konrad, Kai R. and Nagel, Georg and Wrzaczek, Michael and Cascaro, Léa and Vinet, Pauline and Durand, Pauline and Asnacios, Atef and Verma, Lokesh and Bennett, Malcolm J. and Pandey, Bipin K. and Friml, Jiří}, issn = {1095-9203}, journal = {Science}, number = {6795}, pages = {296--300}, publisher = {AAAS}, title = {{Calcium-triggered apoplastic ROS bursts balance gravity and mechanical signals for soil navigation}}, doi = {10.1126/science.adu8197}, volume = {392}, year = {2026}, } @article{21777, abstract = {The advantageous characteristics attributed to the 19F nucleus have made it a popular target for nuclear magnetic resonance (NMR) once again in recent years. Aside from solution NMR, an increasing number of studies have been conducted applying solid-state magic-angle spinning (MAS) NMR to fluorine-labelled samples. Here, the high chemical shift anisotropy and strong dipolar couplings can be utilised to get structural insights into proteins and measure long distances. Despite increasing popularity and promising benefits, the sensitivity of biomolecular 19F MAS NMR often suffers from slow longitudinal T1 relaxation and therefore long recycle delays. In this work, we expand paramagnetic doping, an approach commonly used to reduce proton T1 relaxation times, to 19F-labelled biological samples. We study the effect of Gd(DTPA) and Gd(DTPA-BMA) on 19F T1 and T2, and 13C T1 and T2 relaxation in a [5-19F13C]-tryptophan-labelled protein via 19F-detected MAS NMR experiments. The observed paramagnetic relaxation enhancement substantially reduces measurement times of 19F MAS NMR experiments without compromising resolution. Additionally, we report the chemical shift assignments of all four fluorotryptophan signals in the 12×39 kDa-large protein TET2 using a mutagenesis approach.}, author = {Becker, Lea Marie and Toscano, Giorgia and Kapitonova, Anna and Singh, Rajkumar and Guillerm, Undina and Lichtenecker, Roman J. and Schanda, Paul}, issn = {2699-0016}, journal = {Magnetic Resonance}, number = {1}, pages = {29--37}, publisher = {Copernicus Publications}, title = {{Accelerated 19F biomolecular magic-angle spinning NMR with paramagnetic dopants}}, doi = {10.5194/mr-7-29-2026}, volume = {7}, year = {2026}, } @article{21780, abstract = {It is predicted that half or more of all cataclysmic variables (CVs) should have evolved past the period minimum and now exist as so-called period bouncers where a white dwarf should be accreting from a Roche lobe filling substellar companion. However, this prediction stands in stark contrast to observations, where only a few per cent of CVs are found in this evolutionary phase. A potential solution to this discrepancy is that a magnetic field emerges from within the white dwarf after the system has reached the period minimum. The transfer of angular momentum from the spin of the white dwarf into the orbit then pushes the two stars apart, detaching them for potentially billions of years. Here we present the discovery of ZTF J021804.16+071152.93, a detached 0.69 +- 0.01 M⁠, 19 MG magnetic white dwarf plus 37 +- 5MJup brown dwarf binary with an orbital period of 1.7 h. The kinematics of the system indicate that it is a high probability member of the Galactic thick disc. However, this strongly disagrees with the much younger age of the system obtained from the white dwarf parameters, implying that the system may have been accreting in the past. This system is therefore consistent with having detached as a result of the emergence of the magnetic field of the white dwarf when the system was still mass transferring, and may represent the ultimate fate for many (perhaps even most) CVs.}, author = {Parsons, S. G. and Brown, A. J. and Casewell, S. L. and Littlefair, S. P. and van Roestel, Joannes C and Rebassa-Mansergas, A. and Murillo-Ojeda, R. and Zorotovic, M. and Schreiber, M. R. and Bagnulo, S. and Stroet, M. A. and Castro Segura, N. and Dhillon, V. S. and Dyer, M. J. and Garbutt, J. A. and Green, M. J. and Jarvis, D. and Kennedy, M. R. and Kerry, P. and Mccormac, J. and Munday, J. and Pelisoli, I. and Pike, E. and Sahman, D. I. and Yates, A.}, issn = {1365-2966}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {4}, publisher = {Oxford University Press}, title = {{ZTF J021804.16+071152.93: A dead cataclysmic variable and potential solution to the missing period bouncer cataclysmic variables}}, doi = {10.1093/mnras/stag521}, volume = {547}, year = {2026}, } @article{21779, abstract = {Acidomycin is an anti-mycobacterial antibiotic with a unique mode of action, targeting the biotin biosynthesis pathway. Despite being highly active against mycobacteria in vitro, its development as an anti-tubercular agent has been hindered due to suboptimal pharmacokinetics. Engineering of the acidomycin biosynthesis may yield new analogues with improved pharmacological properties. Here, we describe the identification of the acidomycin biosynthetic gene cluster (BGC) in a Streptomyces bacterium isolated from the rhizosphere of Edelweiss. Notably, the acidomycin BGC is located in proximity to the genes for the biosynthesis of stravidins, secondary metabolites targeting a different enzyme in the biotin biosynthesis pathway, and two genes for streptavidins, proteins that strongly bind and sequester biotin. The identity of the acidomycin BGC was confirmed via both gene knock-out and heterologous expression, which suggested that the fatty acid required for the formation of acidomycin's acyl chain is most likely scavenged from the biotin biosynthesis pathway. CRISPR/Cas9-assisted knock-out of the cytochrome P450-encoding gene in the acidomycin BGC resulted in a significant decrease in its yield but did not abrogate the biosynthesis completely.}, author = {Vignolle, Anna and Zehl, Martin and Garzón, Jaime Felipe Guerrero and Schneider, Olha and Gafriller, Johannes and Grienke, Ulrike and Kirkegaard, Rasmus H. and Zotchev, Sergey B.}, issn = {1751-7915}, journal = {Microbial Biotechnology}, number = {4}, publisher = {Wiley}, title = {{Identification and characterisation of the gene cluster governing biosynthesis of the anti-mycobacterial antibiotic acidomycin}}, doi = {10.1111/1751-7915.70357}, volume = {19}, year = {2026}, } @article{21776, abstract = {Pyridyl motifs equipped with N-substituents can be powerful ligands for catalysis, yet their broader adoption is limited by the lack of a practical method to prepare these scaffolds. We report a modular, robust, and versatile Buchwald–Hartwig amination protocol that enables the rapid synthesis of bipyridine, phenanthroline, terpyridine, and pybox ligands bearing dialkylamine, diarylamine, and heteroaromatic N-substituents. These conditions streamline ligand library synthesis and will facilitate systematic studies in catalysis and related applications.}, author = {Petrik, Adam and Bena, Aleksander and Baunis, Haralds and Kelch, Riley M. and Yoon, Tehshik P. and Pieber, Bartholomäus}, issn = {1615-4169}, journal = {Advanced Synthesis & Catalysis}, number = {9}, publisher = {Wiley}, title = {{Facile access to N-substituted pyridyl ligands}}, doi = {10.1002/adsc.70417}, volume = {368}, year = {2026}, } @article{21781, abstract = {Given a set A of n points (vertices) in general position in the plane, the complete geometric graph Kn[A] consists of all (n2) segments (edges) between the elements of A. It is known that the edge set of every complete geometric graph on n vertices can be partitioned into O(n3∕2) crossing-free paths (or matchings). We strengthen this result under various additional assumptions on the point set. In particular, we prove that for a set A of n randomly selected points, uniformly distributed in [0,1]2, with probability tending to 1 as n→∞, the edge set of Kn[A] can be covered by O(nlogn) crossing-free paths and by O(n√logn) crossing-free matchings. On the other hand, we construct n-element point sets such that covering the edge set of Kn[A] requires a quadratic number of monotone paths.}, author = {Dumitrescu, Adrian and Pach, János and Saghafian, Morteza and Scott, Alex}, issn = {2996-220X}, journal = {Combinatorics and Number Theory}, number = {1}, pages = {73--82}, publisher = {Mathematical Sciences Publishers}, title = {{Covering complete geometric graphs by monotone paths}}, doi = {10.2140/cnt.2026.15.73}, volume = {15}, year = {2026}, } @article{21753, abstract = {The origin(s) of life (OoL), which has puzzled scientists for centuries, remains a major scientific challenge in the 21st century. Understanding the processes relevant to the OoL demands theoretical frameworks that can connect processes across scales, from microscopic dynamics to emergent levels of organization. While experimental studies generate a wealth of data, theoretical and computational approaches provide the structure necessary to interpret and generalize these findings. In Part 1, we examined the most widely used experimental techniques in the field. Here, we focus on the mathematical, physical, and computational techniques used to model phenomena relevant to life’s origin(s). We discuss methods ranging from quantum chemistry and molecular dynamics to chemical reaction networks, autocatalysis, and evolutionary modeling, as well as information-theoretic and phylogenetic approaches that link chemical and biological organization. We further highlight emerging trends such as synthetic biology, omics-based methods, and laboratory automation as novel points of contact for theory-experiment integration. Ultimately, we aim to provide an educational tool that can facilitate more post-disciplinary collaborations in OoL research by helping scientists understand what they can do about the problem of life’s origins, rather than telling them how to think about it.}, author = {Asche, Silke and Bautista, Carla and Blanco, Celia and Boulesteix, David and Champagne-Ruel, Alexandre and Mathis, Cole and Markovitch, Omer and Peng, Zhen and Dass, Avinash Vicholous and Adams, Alyssa and Camprubi, Eloi and Colizzi, Enrico Sandro and Colón-Santos, Stephanie and Dromiack, Hannah and Erastova, Valentina and Garcia, Amanda and Grimaud, Ghjuvan and Halpern, Aaron and Harrison, Stuart A. and Jordan, Seán F. and Jia, Tony Z. and Kahana, Amit and Kolchinsky, Artemy and Moron-Garcia, Odin and Mizuuchi, Ryo and Nan, Jingbo and Orlova, Yuliia and Pearce, Ben K.D. and Paschek, Klaus and Preiner, Martina and Pinna, Silvana and Rodríguez-Román, Eduardo and Schwander, Loraine and Sharma, Siddhant and Smith, Harrison B. and Vieira, Andrey and Xavier, Joana C.}, issn = {2666-3864}, journal = {Cell Reports Physical Science}, number = {4}, publisher = {Elsevier}, title = {{What it takes to solve the origins of life: An integrated review. Part 2: Theoretical methods and emerging trends}}, doi = {10.1016/j.xcrp.2026.103211}, volume = {7}, year = {2026}, } @article{21778, abstract = {We prove that every 𝐿-bilipschitz mapping ℤ 2 → ℝ2 canbe extended to a 𝐶(𝐿)-bilipschitz mapping ℝ2 → ℝ2,and we provide a polynomial upper bound for 𝐶(𝐿).Moreover, we extend the result to every separated netin ℝ2 instead of ℤ 2, with the upper bound gaininga polynomial dependence on the separation and netconstants associated to the given separated net. Thisanswers an Oberwolfach question of Navas from 2015and is also a positive solution of the two-dimensionalform of a decades old open (in all dimensions at leasttwo) problem due to Alestalo Trotsenko and Väisälä.}, author = {Dymond, Michael and Kaluza, Vojtech}, issn = {1469-7750}, journal = {Journal of the London Mathematical Society}, number = {4}, publisher = {Wiley}, title = {{Planar bilipschitz extension from separated nets}}, doi = {10.1112/jlms.70540}, volume = {113}, year = {2026}, } @article{21754, abstract = {The origin(s) of life (OoL), which has puzzled scientists for centuries, remains a major scientific challenge in the 21st century. Research on OoL spans many disciplines, including chemistry, physics, biology, planetary sciences, computer science, and mathematics. The sheer number of different scientific perspectives relevant to the problem has resulted in the coexistence of diverse tools, techniques, data, and software in OoL studies. This has made communication between the disciplines relevant to the OoL extremely difficult because the interpretation of data, analyses, or standards of evidence varies dramatically. Here, we hope to bridge this wide field of study by providing common ground via the consolidation of techniques rather than positing a unifying view on how life emerges. In part 1 of this review, we cover common experimental techniques that have been used significantly in OoL studies in recent years, while in part 2, we review theoretical, computational, and integrative methods. Here, we discuss the use of spectroscopy, spectrometry, chromatography, microscopy, and sequencing methods for characterizing diverse materials. We further discuss the role of data repositories in facilitating the analysis and dissemination of experimental data. This review provides a baseline expectation and understanding of the analytical aspects of origins’ research. Ultimately, we aim to provide an educational tool that can facilitate more post-disciplinary collaborations in OoL research by helping scientists understand what they can do about the problem of life’s origins, rather than telling them how to think about it.}, author = {Asche, Silke and Bautista, Carla and Blanco, Celia and Boulesteix, David and Champagne-Ruel, Alexandre and Mathis, Cole and Markovitch, Omer and Peng, Zhen and Dass, Avinash Vicholous and Adams, Alyssa and Camprubi, Eloi and Colizzi, Enrico Sandro and Colón-Santos, Stephanie and Dromiack, Hannah and Erastova, Valentina and Garcia, Amanda and Grimaud, Ghjuvan and Halpern, Aaron and Harrison, Stuart A. and Jordan, Seán F. and Jia, Tony Z. and Kahana, Amit and Kolchinsky, Artemy and Moron-Garcia, Odin and Mizuuchi, Ryo and Nan, Jingbo and Orlova, Yuliia and Pearce, Ben K.D. and Paschek, Klaus and Preiner, Martina and Pinna, Silvana and Rodríguez-Román, Eduardo and Schwander, Loraine and Sharma, Siddhant and Smith, Harrison B. and Vieira, Andrey and Xavier, Joana C.}, issn = {2666-3864}, journal = {Cell Reports Physical Science}, number = {4}, publisher = {Elsevier}, title = {{What it takes to solve the origin of life: An integrated review. Part 1–Experimental methods and data repositories}}, doi = {10.1016/j.xcrp.2026.103212}, volume = {7}, year = {2026}, } @article{21846, abstract = {We compile a sample of 83 little red dots (LRDs) with JWST imaging and find that a substantial fraction (∼43%, rising to ≳80% for the most luminous LRDs) host one or more spatially offset, UV-bright companions at projected separations of 0.5 kpc ≲ d ≲ 5 kpc, with median 〈d〉 = 1.0 kpc. This fraction is even higher when smaller spatial scales are probed at high signal-to-noise ratio: the two most strongly lensed LRDs, A383-LRD1 and the newly discovered A68-LRD1, both have UV-bright companions at separations of only d ∼ 0.3 kpc, below the resolution limit of most unlensed JWST samples. We explore whether these ubiquitous red/blue configurations may be physically linked to the formation of LRDs, in analogy with the “synchronized pair” scenario originally proposed for direct-collapse black hole formation. In this picture, UV radiation from the companions, with typically modest stellar masses (M∗ ∼ 108−109 M⊙), suppresses molecular hydrogen cooling in nearby gas, allowing nearly isothermal collapse and the formation of extremely compact objects, such as massive black holes, supermassive stars, or quasi-stars. Using component-resolved photometry and spectral energy distribution modeling, we infer Lyman–Werner radiation fields of J21,LW ∼ 102.5–105 at the locations of the red components, comparable to those required in direct-collapse models, suggesting that the necessary photodissociation conditions are realized in many LRD systems. This framework provides a simple and self-consistent explanation for the extreme compactness and distinctive spectral properties of LRDs and links long-standing theoretical models for early compact object formation directly to a population now observed with JWST in the early Universe.}, author = {Baggen, Josephine F.W. and Scoggins, Matthew T. and Van Dokkum, Pieter and Haiman, Zoltán and Torralba Torregrosa, Alberto and Matthee, Jorryt J}, issn = {2041-8213}, journal = {The Astrophysical Journal Letters}, number = {1}, publisher = {IOP Publishing}, title = {{Connecting the dots: UV-bright companions of Little Red Dots as Lyman–Werner sources enabling direct-collapse Black Hole formation}}, doi = {10.3847/2041-8213/ae58a5}, volume = {1002}, year = {2026}, } @article{21845, abstract = {UTe2 exhibits the remarkable phenomenon of re-entrant superconductivity, whereby the zero-resistance state reappears above 40 tesla after being suppressed with a field of around 10 tesla. One potential pairing mechanism, invoked in the related re-entrant superconductors UCoGe and URhGe, involves transverse fluctuations of a ferromagnetic order parameter. However, the requisite ferromagnetic order—present in both UCoGe and URhGe—is absent in UTe2, and neutron scattering shows instead that the magnetic susceptibility is peaked at an antiferromagnetic wavevector. Here, we measure the magnetotropic susceptibility of UTe2 across two field-angle planes. This quantity is sensitive to the magnetic susceptibility in a direction transverse to the applied magnetic field—a quantity that is not accessed in conventional magnetization measurements. We observe a very large decrease in the magnetotropic susceptibility over a broad range of field orientations, indicating a large increase in the transverse magnetic susceptibility. Because our technique probes the magnetic susceptibility in the long wavelength (q = 0) limit, this suggests that the strong transverse susceptibility arises from ferromagnetic spin fluctuations. These ferromagnetic fluctuations are likely important for understanding the pairing mechanism in UTe2, as all three superconducting phases of UTe2 surround this region of enhanced susceptibility in the field-angle phase diagram.}, author = {Zambra, Valeska and Nathwani, Amit and Nauman, Muhammad and Lewin, Sylvia K. and Frank, Corey E. and Butch, Nicholas P. and Shekhter, Arkady and Ramshaw, B. J. and Modic, Kimberly A}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Giant transverse magnetic fluctuations at the edge of re-entrant superconductivity in UTe2}}, doi = {10.1038/s41467-026-71899-7}, volume = {17}, year = {2026}, } @article{21847, abstract = {Analog quantum simulators provide access to many-body dynamics beyond the reach of classical computation. However, extracting physical insights from experimental data is often hindered by measurement noise, limited observables, and incomplete knowledge of the underlying microscopic model. Here, we develop a machine learning approach based on a variational autoencoder (VAE) to analyze interference measurements of tunnel-coupled one-dimensional Bose gases, which realize the sine-Gordon quantum field theory. Trained in an unsupervised manner, the VAE learns a minimal latent representation that strongly correlates with the equilibrium control parameter of the system. Applied to nonequilibrium protocols, the latent space uncovers signatures of frozen-in solitons following rapid cooling, and reveals anomalous postquench dynamics not captured by conventional correlation-based methods. These results demonstrate that generative models can extract physically interpretable variables directly from noisy and sparse experimental data, providing complementary probes of equilibrium and nonequilibrium physics in quantum simulators. More broadly, our work highlights how machine learning can supplement established field-theoretical techniques, paving the way for scalable, data-driven discovery in quantum many-body systems.}, author = {Moller, Frederik Skovbo and Fernández-Fernández, Gabriel and Schweigler, Thomas and De Schoulepnikoff, Paulin and Schmiedmayer, Jörg and Muñoz-Gil, Gorka}, issn = {2643-1564}, journal = {Physical Review Research}, number = {2}, publisher = {American Physical Society}, title = {{Learning minimal representations of many-body physics from snapshots of a quantum simulator}}, doi = {10.1103/r7pj-gl7r}, volume = {8}, year = {2026}, } @misc{21174, abstract = {UTe2 exhibits the remarkable phenomenon of re-entrant superconductivity, whereby the zero-resistance state reappears above 40 tesla after being suppressed with a field of around 10 tesla. One potential pairing mechanism, invoked in the related re-entrant superconductors UCoGe and URhGe, involves transverse fluctuations of a ferromagnetic order parameter. However, the requisite ferromagnetic order - present in both UCoGe and URhGe - is absent in UTe2, and magnetization measurements show no sign of strong fluctuations. Here, we measure the magnetotropic susceptibility of UTe2 across two field-angle planes. This quantity is sensitive to the magnetic susceptibility in a direction transverse to the applied magnetic field - a quantity that is not accessed in conventional magnetization measurements. We observe a very large decrease in the magnetotropic susceptibility over a broad range of field orientations, indicating a large increase in the transverse magnetic susceptibility. The three superconducting phases of UTe2, including the high-field re-entrant phase, surround this region of enhanced susceptibility in the field-angle phase diagram. The strongest transverse susceptibility is found near the critical end point of the high-field metamagnetic transition, suggesting that quantum critical fluctuations of a field-induced magnetic order parameter may be responsible for the large transverse susceptibility, and may provide a pairing mechanism for field-induced superconductivity in UTe2.}, author = {Modic, Kimberly A}, keywords = {transverse magnetic susceptibility, magnetotropic, superconductivity, magnetic fluctuations}, publisher = {Institute of Science and Technology Austria}, title = {{Research data for "Giant transverse magnetic fluctuations at the edge of re-entrant superconductivity in UTe2"}}, doi = {10.15479/AT-ISTA-21174}, year = {2026}, } @article{21849, abstract = {The development of complex tissues relies on the precise assignment of cell identity. At the molecular scale, this process depends on the deposition of epigenetic modifications—such as methylation—that are regulated by complex biochemical networks and occur at specific regions on the DNA and chromatin. Here we show that despite the complexity of epigenetic regulation, dynamical scaling and self-similarity of DNA methylation marks emerge in embryonic development. Drawing on single-cell multi-omics experiments, super-resolution microscopy and statistical physics, we demonstrate that these phenomena originate in dynamical feedback between DNA methylation and the formation of nanoscale dynamic chromatin aggregates. These nanoscale processes lead to genome-wide increase in DNA methylation marks following a power law and self-similar correlation functions. Using this framework, we identify methylation patterns that precede gene expression changes in embryonic symmetry breaking. Our work identifies linear sequencing measurements as a laboratory to study mesoscopic biophysical processes in vivo.}, author = {Olmeda, Fabrizio and Lohoff, Tim and Kafetzopoulos, Ioannis and Clark, Stephen J. and Benson, Laura and Santos, Fatima and Krueger, Felix and Walker, Simon and Reik, Wolf and Rulands, Steffen}, issn = {1745-2481}, journal = {Nature Physics}, publisher = {Springer Nature}, title = {{Scaling and self-similarity in the formation of the embryonic epigenome}}, doi = {10.1038/s41567-026-03263-x}, year = {2026}, } @article{21848, abstract = {Despite the success of mRNA therapeutics, challenges remain in optimizing immune responses and minimizing side effects. Cell-specific antigen delivery may help reduce required doses and improve vaccine efficacy. In this study, we report on a targeted delivery system for mRNA to a specific subset of skin-resident antigen-presenting cells: Langerhans cells. By functionalizing lipid nanoparticles with a langerin-specific glycomimetic ligand, we achieve selective mRNA delivery to both murine and human primary Langerhans cells with minimal off-target uptake, at the same time resulting in significantly increased mRNA translation. This targeted mRNA delivery not only enhances antigen presentation and T-cell responses but also enables dose-sparing and superior antitumor immunity compared with conventional immunization in a B16-OVA tumor model. Importantly, our platform’s high compatibility with various lipid nanoparticle formulations offers a flexible and precise tool for skin-directed mRNA delivery.}, author = {Klein, Klara and Johnson, Litty and Rîca, Ramona and Sarcevic, Mirza and Carta, Gabriele and Seiser, Saskia and Elbe-Bürger, Adelheid and Langer, Freyja and Rahhal, Nowras and Rademacher, Christoph and Wawrzinek, Robert and Quattrone, Federica and Sparber, Florian}, issn = {1523-1747}, journal = {Journal of Investigative Dermatology}, publisher = {Elsevier}, title = {{Langerhans cell–targeted mRNA delivery: A strategy for dose-sparing and enhanced antitumor immunity}}, doi = {10.1016/j.jid.2026.03.026}, year = {2026}, } @article{21844, abstract = {Little red dots (LRDs) are a newly identified class of broad-line active galactic nuclei (AGNs) with a distinctive V-shaped spectrum characterized by red optical and blue UV continuum emission. Their high abundance at redshifts of z ∼ 6–8 and decline at lower redshifts suggest a transient origin. We propose that the spectral shape of LRDs originates from compact binary black hole systems, in which each black hole is surrounded by a mini-disk and embedded within a larger circumbinary disk. With a binary separation of ≲103 Schwarzschild radii, the Wien tail of a T ≃ 5000 K blackbody spectrum at the inner edge of the circumbinary disk produces the red optical emission, while the mini-disks power the UV continuum. Binary torques carve out a gap between the circumbinary disk and the mini-disks, setting the turnover wavelength of the V-shaped spectrum around the Balmer limit. This scenario naturally reproduces LRD spectra requiring only modest dust attenuation (AV ≲ 1 mag), resolving overestimated luminosities for LRDs in previous studies and alleviating a tension with the so-called Sołtan argument. This model predicts distinct spectral evolution as the binary orbit decays through binary disk interactions and gravitational-wave (GW) emission, linking early-stage “proto-LRD” binaries to the broader AGN population and late-stage “LRD descendants” to coalescing binaries detectable in GW experiments.}, author = {Inayoshi, Kohei and Shangguan, Jinyi and Chen, Xian and Ho, Luis C. and Haiman, Zoltán}, issn = {1538-4357}, journal = {The Astrophysical Journal}, number = {1}, publisher = {IOP Publishing}, title = {{The emergence of Little Red Dots from binary massive black holes}}, doi = {10.3847/1538-4357/ae548d}, volume = {1002}, year = {2026}, } @article{21860, abstract = {Glutamate excitotoxicity is a cell death mechanism triggered by accumulation of glutamate in the extracellular space. The α-ketoglutarate dehydrogenase complex (αKGDHC), an enzyme of the tricarboxylic acid cycle, represents a branching point controlling glutamate formation and its consumption as a fuel. Hence, modulation of the activity of αKGDHC might alter the amount of glutamate available for excitotoxic effects. To address this hypothesis, hippocampal neurons in primary co-culture with glial cells were exposed to zero-Mg2 buffer to elicit excitotoxicity through N-methyl-D-aspartic acid (NMDA) receptor disinhibition. Pretreatment of the cultures with succinyl phosphonate, to inhibit αKGDHC, enhanced excitotoxity, whereas promotion of αKGDHC activity by pretreatment with thiamine caused an opposite action. Moreover, NMDA receptor currents – but not those mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors – were potentiated in neurons with impaired αKGDHC activity and diminished in neurons with boosted αKGDHC activity. The sensitization of NMDA receptors involved mGluR1 activation and was accompanied by enhanced neuronal discharge activity, elevated basal cytosolic Ca2+ levels, and augmented Ca2+ responses evoked by glutamate application. These results suggest that mGluR1-mediated potentiation of NMDA receptors contributes to a mechanism by which inhibition of αKGDHC might exacerbate glutamate excitotoxicity.}, author = {Goeschl, Vanessa and Hotka, Matej and Hochreiter, Bernhard and Hilber, Karlheinz and Boehm, Stefan and Kozlov, Andrey V. and Kubista, Helmut}, issn = {1477-9137}, journal = {Journal of Cell Science}, number = {8}, publisher = {The Company of Biologists}, title = {{α-ketoglutarate dehydrogenase complex activity modulates glutamate excitotoxicity via metabotropic regulation of NMDA receptors in primary cultures}}, doi = {10.1242/jcs.264420}, volume = {139}, year = {2026}, } @article{21842, abstract = {AM CVn stars are ultra-compact semi-detached binaries consisting of a white dwarf primary and a hydrogen-depleted secondary. In this paper, we present spectroscopic and photometric results of 15 transient sources pre-classified as AM CVn candidates. Our analysis confirms 9 systems of the type AM CVn, 3 hydrogen-rich cataclysmic variables (accreting white dwarfs with near-main-sequence stars for donors), and 3 systems that could be evolved cataclysmic variables. Eight of the AM CVn stars are analysed spectroscopically for the first time, which increases the number of spectroscopically confirmed AM CVns by about 10%. TESS data revealed the orbital period of the AM CVn star ASASSN-20pv to be Porb =27.282 min, which helps to constrain the possible values of its mass ratio. TESS also helped to determine the superhump periods of one AM CVn star (ASASSN-19ct, Psh =30.94 min) and two cataclysmic variables we classify as WZ Sge stars (Psh =90.77 min for ZTF18aaaasnn and Psh =91.6min for ASASSN-15na).We identified very different abundances in the spectra of theAM CVns binaries ASASSN-15kf and ASASSN-20pv (both Porb ∼27.5min), suggesting different type of donors. Six of the studied AMCVns are X-ray sources, which helped to determine their mass accretion rates. Photometry shows that the duration of all the superoutbursts detected in the AM CVns is consistent with expectations from the disc instability model. Finally, we provide refined criteria for the identification of new systems using all-sky surveys such as LSST.}, author = {Kára, Jan and Rivera Sandoval, Liliana and Mendoza, Wendy and Maccarone, Thomas and Pichardo Marcano, Manuel and Salazar Manzano, Luis E. and Oelkers, Ryan J. and van Roestel, Joannes C}, issn = {1448-6083}, journal = {Publications of the Astronomical Society of Australia}, publisher = {Cambridge University Press}, title = {{A study of transients from ground-based surveys reveals new ultra-compact accreting white dwarf binaries}}, doi = {10.1017/pasa.2026.10184}, volume = {43}, year = {2026}, } @misc{21864, author = {Anonymous, 1 and Anonymous, 2 and Anonymous, 3}, issn = {2664-1690}, pages = {32}, publisher = {Institute of Science and Technology Austria}, title = {{Mechanism of tissue tension homeostasis during embryogenesis}}, year = {2026}, } @article{21837, abstract = {In a warming world of glacier changes, the scientific community has dedicated increasing attention to debris-covered glaciers and their response to climate. A variety of models with distinct complexity and data requirements have been developed and widely used to simulate melt under debris at different sites and scales, but their skills have never been compared. As part of the activities of the International Association of Cryospheric Sciences (IACS) Debris Covered Glacier Working Group, we present an intercomparison exercise aimed at advancing our understanding of model skills in simulating ice melt under a debris layer. We compare 15 models with different complexity at nine sites in the European Alps, Caucasus, Chilean Andes, Nepalese Himalaya and the Southern Alps of New Zealand, over one melt season. We run the models with measured meteorological data from automatic weather stations and estimated or measured debris properties. We consider four main model categories: (i) energy balance models that calculate melt by solving the physics of heat transfer to the debris layer, but require a high amount of input data; (ii) a simplified energy balance model; (iii) enhanced temperature-index models; and (iv) simple empirical temperature-index models that have been extensively used given their low data requirement but require calibration of their empirical parameters. Model performance is evaluated using on-site measurements of sub-debris melt (for all models) and surface temperature (for models based on the surface energy balance). Our results show that physically-based energy balance models and empirical temperature-index models perform in a distinct manner. At one end of the spectrum, simple temperature-index models are accurate when recalibrated or when using site-specific literature parameters, and show poor results when parameters are uncalibrated. At the other end, energy balance models show a range of performance: the most accurate energy balance models are those with the highest degree of complexity at the atmosphere-debris interface. An important data gap emerged from our experiment: the poor performance of all models at three sites was related to the poor knowledge of debris properties, and specifically of thermal conductivity. Future work should focus on both: (i) consistent data acquisition to evaluate existing models and support new model developments; (ii) advancing models by accounting for processes such as debris-snow interactions, moisture in the debris and refreezing. We suggest that a systematic effort of model development using a common model framework could be carried out in phase II of the Working Group.}, author = {Pellicciotti, Francesca and Fontrodona-Bach, Adrià and Rounce, David R. and Fyffe, Catriona Louise and Anderson, Leif S. and Ayala, Álvaro and Brock, Ben W. and Buri, Pascal and Fugger, Stefan and Fujita, Koji and GANTAYAT, PRATEEK and Groos, Alexander R. and Immerzeel, Walter and Kneib, Marin and Mayer, Christoph and MacDonell, Shelley and McCarthy, Michael and McPhee, James and Miles, Evan and Purdie, Heather and Rets, Ekaterina and Sakai, Akiko and Shaw, Thomas and Steiner, Jakob and Wagnon, Patrick and Winter-Billington, Alex}, issn = {1994-0424}, journal = {The Cryosphere}, number = {3}, pages = {1895--1928}, publisher = {Copernicus Publications}, title = {{DCG-MIP: The debris-covered glacier melt model intercomparison experiment}}, doi = {10.5194/tc-20-1895-2026}, volume = {20}, year = {2026}, }