@article{22718, abstract = {Both Newtonian and non-Newtonian fluids may exhibit complex slip behaviour at the boundary. We examine a broad class of slip boundary conditions that generalises the commonly used Navier slip, perfect slip, stick-slip and Tresca friction boundary conditions. In particular, set-valued, nonmonotone, noncoercive and dynamic relations may occur. For a unifying framework of such relations, we present a fully discrete numerical scheme for the time-dependent Navier–Stokes equations subject to impermeability and general slip-type boundary conditions on polyhedral domains. Based on compactness arguments, we prove convergence of subsequences, finally ensuring the existence of a weak solution. The numerical scheme uses a general inf-sup stable pair of finite element spaces for the velocity and pressure, a regularisation approach for the implicit slip boundary condition and, most importantly, a general Nitsche method to impose the impermeability and a backward Euler time stepping. One of the key tools in the convergence proof is an inhomogeneous Korn inequality that includes a normal trace term.}, author = {Gazca-Orozco, Pablo Alexei and Gmeineder, Franz and Maringová, Erika and Tscherpel, Tabea}, issn = {1793-6314}, journal = {Mathematical Models and Methods in Applied Sciences}, publisher = {World Scientific Publishing}, title = {{A Nitsche method for incompressible fluids with general dynamic boundary conditions}}, doi = {10.1142/S0218202526500508}, year = {2026}, } @article{22734, abstract = {Silver selenide (Ag2Se) is a promising near-room-temperature thermoelectric material, but its narrow stoichiometric window and β–α phase transition complicate reproducible microstructure control. Here, we present a mismatch-assisted microstructure engineering strategy in which Ag2Se particles are treated with polyanionic ZnSe complexes and consolidated through the β–α transition to introduce ZnSe nanoprecipitates, Ag2Se/ZnSe interfaces, and local strain fields. The crystallographic mismatch between ZnSe and Ag2Se, together with the Zn2+/Ag+ size difference, amplifies phase-transition-induced deformation and promotes high-density dislocations with periodic strain modulations. This defect architecture suppresses grain coarsening, removes excess Ag, limits Ag-interstitial formation, and reduces lattice thermal conductivity through lattice softening and multiscale phonon scattering. Ag2Se–4%ZnSe nanocomposites achieve a peak zTmax of 1.13 at 369 K and a zTavg of 1.08 from 300 to 380 K, demonstrating mismatch-driven defect engineering through the β–α phase transition as a route for optimizing Ag2Se-based thermoelectrics.}, author = {Liu, Yu and Kleinhanns, Tobias and Spadaro, Maria Chiara and Genç, Aziz and Horta, Sharona and Navita, Navita and Costanzo, Tommaso and Dutkiewicz, Ewelina and Arbiol, Jordi and Hong, Min and Ibáñez, Maria}, issn = {2380-8195}, journal = {ACS Energy Letters}, number = {8}, pages = {5752--5762}, publisher = {American Chemical Society}, title = {{Exploiting mismatch strain and the β–α phase transition for microstructural engineering in thermoelectric Ag2Se}}, doi = {10.1021/acsenergylett.6c01499}, volume = {11}, year = {2026}, } @article{22715, abstract = {Grazing-incidence small-angle scattering (GISAS) is a relatively young technique with important applications in thin-film technology and untapped potential when it comes to 2D analysis on an absolute intensity scale. Approaching standardization and reference methods early is foundational for reproducibility and comparability across laboratories and reduction of systematic error sources. It underpins trust in data obtained and accelerates innovation by ensuring that scientists work from a common methodological baseline. Accordingly, obtaining reproducible results from different GISAS instruments requires an agreement on how measurements are performed, instruments calibrated and terms defined. To pave the way for standardization and reference methods, we surveyed GISAS practitioners on what comes before an experiment: hardware, software, sample alignment and instrument calibration. Twenty-two questions were designed to elucidate the state of the art, which can be used for the development of reference methods. Our data on 27 instruments provide the basis for standardization. With very few exceptions, we found laboratories prepared to implement future reference methods, but no consensus emerges naturally for sample alignment and instrument calibration. We, that is the GISAS community, are thus in a position to embark on the journey of standardization.}, author = {Hörmann, Anja F. and Balazs, Daniel and Breßler, Ingo and Klokic, Sumea and Moradi, Melika and Solano, Eduardo and Stellhorn, Annika and Pauw, Brian R.}, issn = {1600-5767}, journal = {Journal of Applied Crystallography}, keywords = {grazing incidence, reference methods, calibration, standardization, community}, number = {4}, pages = {1247--1253}, publisher = {International Union of Crystallography}, title = {{Grazing-incidence scattering surveyed: Towards reference methods for alignment and calibration}}, doi = {10.1107/S1600576726005741}, volume = {59}, year = {2026}, } @article{22716, abstract = {We give an algorithm that, with high probability, maintains a (1-ε)-approximate s-t maximum flow in undirected, uncapacitated n-vertex graphs undergoing m edge insertions in Õ(m+ n F^*/ε) total update time, where F^{*} is the maximum flow on the final graph. This is the first algorithm to achieve polylogarithmic amortized update time for dense graphs (m = Ω(n²)), and more generally, for graphs where F^* = Õ(m/n). At the heart of our incremental algorithm is the residual graph sparsification technique of Karger and Levine [SICOMP '15], originally designed for computing exact maximum flows in the static setting. Our main contributions are (i) showing how to maintain such sparsifiers for approximate maximum flows in the incremental setting and (ii) generalizing the cut sparsification framework of Fung et al. [SICOMP '19] from undirected graphs to balanced directed graphs.}, author = {Goranci, Gramoz and Henzinger, Monika H and Räcke, Harald and Sricharan, A. R.}, issn = {1549-6333}, journal = {ACM Transactions on Algorithms}, number = {3}, publisher = {ACM}, title = {{Incremental approximate maximum flow via residual graph sparsification}}, doi = {10.1145/3816252}, volume = {22}, year = {2026}, } @article{22714, abstract = {Radial glial progenitors (RGPs) generate all projection neurons (PNs) in the cerebral cortex through incompletely understood processes. We combined Mosaic Analysis with Double Markers at embryonic stages (E)12.5 and E13.5 with early postnatal callosal tracing to dissect RGP lineage progression. We find that multipotent RGPs generate all extra-telencephalic (ET) and intra-telencephalic (IT) PNs via parallel sublineages that emerge simultaneously at neurogenesis onset. ET-PN production progresses exclusively via small, self-consuming lineages; IT-PN lineages feature RGPs generating large translaminar outputs. The early emergence of IT-PN–fated RGPs, coinciding with a switch to direct neurogenesis, contributes to the stereotyped population-level progression of the multipotent lineage. We also identify POU3F transcription factors as candidate regulators of IT-PN fate via noncanonical mitotic chromatin binding. The results support a model whereby IT- and ET-PNs arise from an early bifurcation and parallel specification within the multipotent RGP lineage.}, author = {Varela Martínez, Irene and Villalba Requena, Ana and García-Marqués, Jorge and Aguilera, Alfonso and Castro, Diogo S. and Hippenmeyer, Simon and Nieto, Marta}, issn = {2375-2548}, journal = {Science Advances}, number = {32}, pages = {eadw5487}, publisher = {AAAS}, title = {{Early fate diversification of radial glial progenitors during corticogenesis}}, doi = {10.1126/sciadv.adw5487}, volume = {12}, year = {2026}, } @article{22733, abstract = {Sleep need is associated with both circuit dynamics and widespread synaptic plasticity, yet the specific synaptic changes underlying sleep homeostasis remain incompletely understood. In Drosophila, sleep loss has been shown to trigger plasticity of the presynaptic active zone, marked by increasing levels of the ELKS-family scaffold protein Bruchpilot (BRP). By titrating brp gene copy number, we previously established a presynapse-specific, dosage-dependent paradigm that modulates sleep pressure. Here, to elucidate the molecular landscape of this plasticity, we performed synapse-enriched integrated-omics. Proteomic and bioinformatic analyses revealed changes in immune and stress response pathways and local translation control. Strikingly, phospho-proteomic analysis uncovered a global shift toward hypophosphorylation, particularly in presynaptic proteins, indicating a reprogramming of the phosphorylation–dephosphorylation balance. This presynaptic hypophosphorylation is likely contributed by reduced activity of Protein Kinase A (PKA) and enhanced substrate affinity of Protein Phosphatase 1 (PP1) mediated by its regulatory subunit Spinophilin (Spn). Manipulating either PKA or PP1 activity was sufficient to suppress BRP-modulated sleep phenotypes. We propose that presynaptic hypophosphorylation constitutes a molecular signature of local synaptic remodeling that adaptively tunes sleep need via reversible posttranslational modification, a mechanism likely conserved across species.}, author = {Piao, Chengji and Dutkiewicz, Ewelina and Kollipara, Laxmikanth and Sickmann, Albert and Huang, Sheng and Sigrist, Stephan J.}, issn = {0027-8424}, journal = {Proceedings of the National Academy of Sciences}, number = {24}, publisher = {National Academy of Sciences}, title = {{Active zone plasticity couples sleep need to presynaptic hypophosphorylation}}, doi = {10.1073/pnas.2524065123}, volume = {123}, year = {2026}, } @article{22712, abstract = {Ginseng (Panax ginseng) derives its renowned therapeutic properties from ginsenoside metabolites. However, the long cultivation cycle and susceptibility to diseases hinder the advancement of the ginseng industry. Here, we demonstrate that the embryonic protoderm of ginseng can efficiently produce ginsenosides. Single-cell transcriptome and mass spectrometry imaging analyses reveal that ginsenosides accumulate in the protoderm of ginseng embryonic callus (EC) at levels comparable to those in forest ginseng. Epigenetic analyses indicate that elevated histone acetylation and enhanced chromatin accessibility at regeneration- and ginsenoside metabolism-related gene loci are associated with the ginsenoside-producing capacity of EC. Increasing histone acetylation levels or overexpressing the regeneration-related WUSCHEL-RELATED HOMEOBOX11 (WOX11) gene further enhances ginsenoside production in EC. Our findings suggest that the protoderm of EC could serve as an in situ biological compartment for high-efficiency ginsenoside producion, offering a complementary approach to traditional ginseng cultivation.}, author = {Liu, Juan and Zhai, Ning and Zhang, Shiyi and Tamada, Yosuke and Li, Tonghui and Zhang, Linfan and Chen, Tong and Wang, Chenglin and Yang, Jian and Gao, Jiaqi and Li, Xiang and Zhou, Junhui and Zhang, Yonghong and Liu, Yu and Wang, Yuan and Friml, Jiří and Benková, Eva and Li, Chen and Xu, Lin and Huang, Luqi}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Single-cell analyses identify the ginseng embryonic protoderm as a native compartment for high-efficiency ginsenoside production}}, doi = {10.1038/s41467-026-74881-5}, volume = {17}, year = {2026}, } @article{22711, abstract = {When charge flows through a molecular circuit, it induces a magnetic field that allows the circuit to behave as a nanoscale electromagnet. However, in single-molecule circuits this magnetic field is usually weak. Here we show that radially π-conjugated carbon structures can support amplified circulating currents that generate local magnetic fields. Within tight-binding and density functional theory (DFT) frameworks, we first study cycloparaphenylene (CPP) junctions where both electrodes are attached to the same phenylene unit on the nanohoop. We observe an energy-dependent ring current component that traverses the whole macrocycle by mapping the local current density. Importantly, we find that destructive interference near degenerate resonances can reverse the ring current direction and amplify it strongly relative to the source–drain current. We show that this interference-driven design principle is general, and also carries over to C60 junctions. In fullerene, lower-lying degenerate resonances are more easily accessible through electrostatic gating, reaching a magnetic field of 14.2 mT under a 100 mV source–drain bias. This work thus provides new insights into ring currents in radially π-conjugated carbon structures and highlights their potential as design platforms for single-molecule electromagnets.}, author = {Shi, Wanzhuo and Korytár, Richard and Evers, Ferdinand and Tovar, John D. and Venkataraman, Latha}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Designing effective single-molecule electromagnets with radially π-conjugated carbon structures}}, doi = {10.1038/s41467-026-74365-6}, volume = {17}, year = {2026}, } @misc{22687, abstract = {Understanding enzyme function requires characterizing not only static structure but also dynamics and ligand interactions. NMR spectroscopy provides this insight at atomic resolution, yet for large proteins the difficulty of resonance assignment has largely confined such studies to systems below ∼50 kDa, or to observing only methyl groups. Here we present an integrated magic-angle spinning (MAS) and solution NMR study of the 134 kDa tetrameric malate dehydrogenase from Ignicoccus islandicus (IiMDH), an enzyme of particular interest as an evolutionary intermediate between allosteric lactate dehydrogenases and non-allosteric malate dehydrogenases. By combining high-dimensional (up to 4D) MAS NMR experiments on sedimented protein with solution NMR, we achieved 92% backbone heavy- atom assignment and 91% assignment of all Ile-δ1, Leu-δ1/-δ2, Val-γ1/-γ2, Met-ε and Thr-γ methyl groups. Building on these assignments, we use various probes of backbone and sidechain dynamics: elevated MAS NMR 15N rotating-frame relaxation (R1ρ) points to microsecond motions in functionally critical regions, including the catalytic loop and the mobile surface loop. Complementary methyl-axis order parameters from solution NMR identified additional flexible sites in the hydrophobic core. Chemical shift perturbation experiments upon addition of the substrate analogue oxamate, monitored via backbone 1H-15N TROSY, revealed both active-site contacts and responses in helices α2F and α3G, regions implicated in allosteric signal transmission. The integrated approach demonstrated here exploits the distinct strengths of MAS and solution NMR, and provides a comprehensive view of structure, dynamics, and substrate interactions in a large oligomeric enzyme that would not be accessible by either technique alone.}, author = {Schanda, Paul and Napoli, Federico}, publisher = {Institute of Science and Technology Austria}, title = {{Data and scripts for: "Integrated solid/solution NMR assignment allows mapping dynamics and ligand binding in a 134 kDa enzyme"}}, doi = {10.15479/AT-ISTA-22687}, year = {2026}, } @article{21746, abstract = {As vertebrates transitioned from water to land, locomotion shifted from undulatory swimming to limb-based movement. How spinal circuits and their cell types evolved to support this transition remains unclear. We leverage frog metamorphosis, which recapitulates this transition within a single organism, to define how spinal circuits generate aquatic versus terrestrial motor patterns. At swim stages, spinal architecture is uniform, with a transcriptionally and anatomically homogeneous motor and interneurons. As limbs develop and their movement complexifies, spinal circuits expand in neuron number and subtype diversity. This expansion is most pronounced for V1 inhibitory neurons, which increase ∼70-fold and diversify into transcriptionally distinct subtypes. Disrupting transcription factors defining emerging motor and V1 populations reveals molecular segregation between swim and limb circuits, highlighting the role of subtype diversity in motor coordination. A multifold increase in inhibitory neuron diversity thus underlies the tail-to-limb locomotor transition, providing a framework for spinal circuit adaptation during vertebrate evolution.}, author = {Vijatovic, David and Toma, Florina Alexandra and Ignatyev, Y and Harrington, Zoe P and Sommer, Christoph M and Hauschild, Robert and Smits, Matthijs Geert and Dalla Vecchia, Marco and Trevisan, Alexandra J. and Chapman, Phillip and Julseth, Mara and Brenner-Morton, Susan and Gabitto, Mariano I. and Dasen, Jeremy S. and Bikoff, Jay B. and Sweeney, Lora Beatrice Jaeger}, issn = {2211-1247}, journal = {Cell Reports}, number = {4}, publisher = {Elsevier}, title = {{Multifold increase in spinal inhibitory cell types with emergence of limb movement}}, doi = {10.1016/j.celrep.2026.117227}, volume = {45}, year = {2026}, } @phdthesis{22667, author = {Vijatovic, David}, isbn = {978-3-99078-082-4}, issn = {2663-337X}, pages = {172}, publisher = {Institute of Science and Technology Austria}, title = {{Dissecting the molecular and functional basis of motor control in the frog Xenopus laevis}}, doi = {10.15479/AT-ISTA-22667}, 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}, } @article{18706, abstract = {We prove discrete-to-continuum convergence for dynamical optimal transport on Zd -periodic graphs with cost functional having linear growth at infinity. This result provides an answer to a problem left open by Gladbach, Kopfer, Maas, and Portinale (Calc Var Partial Differential Equations 62(5), 2023), where the convergence behaviour of discrete boundary-value dynamical transport problems is proved under the stronger assumption of superlinear growth. Our result extends the known literature to some important classes of examples, such as scaling limits of 1 -Wasserstein transport problems. Similarly to what happens in the quadratic case, the geometry of the graph plays a crucial role in the structure of the limit cost function, as we discuss in the final part of this work, which includes some visual representations.}, author = {Portinale, Lorenzo and Quattrocchi, Filippo}, issn = {1469-4425}, journal = {European Journal of Applied Mathematics}, keywords = {optimal transport, discrete-to-continuum, homogenisation, linear growth, gamma-convergence}, number = {3}, pages = {614--642}, publisher = {Cambridge University Press}, title = {{Discrete-to-continuum limits of optimal transport with linear growth on periodic graphs}}, doi = {10.1017/s0956792524000810}, volume = {37}, year = {2026}, } @phdthesis{22694, abstract = {We develop and employ techniques from equivariant algebraic K-theory and related invariants in the context of geometric representation theory, in both arithmetic and topological situations. We showcase the use of such techniques on the affine Grassmannian Gr, a space of fundamental interest in the geometric Langlands program. It is a deep development of mathematics of the last century that many concrete, yet combina- torially complex algebraic problems may be effectively studied through the lens of algebraic geometry. The objects of interest can be often realized as cohomological invariants of algebraic varieties, and good understanding of their geometry sheds light into the original questions. Such techniques have seen immense applications in the Langlands program, where they go under the label of geometric representation theory. One source of powerful invariants in algebraic geometry comes from algebraic K-theory, Hochschild homology, and their relatives. These localizing invariants contain large amount of information, but are quite hard to compute. For this reason, their usage in geometric representation theory has been limited. The aim of this thesis is to showcase how to control such invariants in the situations of interest and use them to obtain new insights. We start by reinterpreting equivariant Hochschild homology in terms of functions on certain fixed-point schemes, which are of independent interest. We compare it to equivariant K-theory via the trace map. We give new computations and comparisons of such invariants of affine Schubert varieties in Gr, including arithmetic situations. We show that they behave much better than expected. We finally utilize this circle of ideas in a purely topological setting. We describe the varying fixed points of the extended torus action on the affine Grassmannian, and use it to compute its equivariant topological K-theory ring. The answer is nontrivial and verifies an outstanding conjecture in the subject. We compare, partly conjecturally, the resulting K-theory ring to the completed center of an integral even hybrid quantum group and its deformed quantum category O. This gives a genuine application of our computations in pure representation theory.}, author = {Löwit, Jakub}, issn = {2663-337X}, pages = {185}, publisher = {Institute of Science and Technology Austria}, title = {{Equivariant K-theory of affine Grassmannians in representation theory and arithmetic}}, doi = {10.15479/AT-ISTA-22694}, year = {2026}, } @article{21751, abstract = {We define a certain class of simple varieties over a field k by a constructive recipe and show how to control their (equivariant) truncating invariants. Consequently, we prove that on simple varieties: (i) if k = k and char k = p, the p-adic cyclotomic trace is an equivalence; (ii) if k = Q, the Goodwillie–Jones trace is an isomorphism in degree zero; (iii) we can control homotopy invariant K-theory KH, which is equivariantly formal and determined by its topological counterparts. Simple varieties are quite special, but encompass important singular examples appearing in geometric representation theory. We, in particular, show that both finite and affine Schubert varieties for GLn lie in this class, so all the above results hold for them. }, author = {Löwit, Jakub}, issn = {1687-0247}, journal = {International Mathematics Research Notices}, number = {7}, publisher = {Oxford University Press}, title = {{Equivariant localizing invariants of simple varieties}}, doi = {10.1093/imrn/rnag058}, volume = {2026}, year = {2026}, } @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}, } @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}, }