@article{11167, abstract = {Complex I is one of the major respiratory complexes, conserved from bacteria to mammals. It oxidises NADH, reduces quinone and pumps protons across the membrane, thus playing a central role in the oxidative energy metabolism. In this review we discuss our current state of understanding the structure of complex I from various species of mammals, plants, fungi, and bacteria, as well as of several complex I-related proteins. By comparing the structural evidence from these systems in different redox states and data from mutagenesis and molecular simulations, we formulate the mechanisms of electron transfer and proton pumping and explain how they are conformationally and electrostatically coupled. Finally, we discuss the structural basis of the deactivation phenomenon in mammalian complex I.}, author = {Kampjut, Domen and Sazanov, Leonid A}, issn = {0959-440X}, journal = {Current Opinion in Structural Biology}, keywords = {Molecular Biology, Structural Biology}, publisher = {Elsevier}, title = {{Structure of respiratory complex I – An emerging blueprint for the mechanism}}, doi = {10.1016/j.sbi.2022.102350}, volume = {74}, year = {2022}, } @article{11179, abstract = {Large oligomeric enzymes control a myriad of cellular processes, from protein synthesis and degradation to metabolism. The 0.5 MDa large TET2 aminopeptidase, a prototypical protease important for cellular homeostasis, degrades peptides within a ca. 60 Å wide tetrahedral chamber with four lateral openings. The mechanisms of substrate trafficking and processing remain debated. Here, we integrate magic-angle spinning (MAS) NMR, mutagenesis, co-evolution analysis and molecular dynamics simulations and reveal that a loop in the catalytic chamber is a key element for enzymatic function. The loop is able to stabilize ligands in the active site and may additionally have a direct role in activating the catalytic water molecule whereby a conserved histidine plays a key role. Our data provide a strong case for the functional importance of highly dynamic - and often overlooked - parts of an enzyme, and the potential of MAS NMR to investigate their dynamics at atomic resolution.}, author = {Gauto, Diego F. and Macek, Pavel and Malinverni, Duccio and Fraga, Hugo and Paloni, Matteo and Sučec, Iva and Hessel, Audrey and Bustamante, Juan Pablo and Barducci, Alessandro and Schanda, Paul}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Functional control of a 0.5 MDa TET aminopeptidase by a flexible loop revealed by MAS NMR}}, doi = {10.1038/s41467-022-29423-0}, volume = {13}, year = {2022}, } @inproceedings{11180, abstract = {Designing and implementing efficient parallel priority schedulers is an active research area. An intriguing proposed design is the Multi-Queue: given n threads and m ≥ n distinct priority queues, task insertions are performed uniformly at random, while, to delete, a thread picks two queues uniformly at random, and removes the observed task of higher priority. This approach scales well, and has probabilistic rank guarantees: roughly, the rank of each task removed, relative to remaining tasks in all other queues, is O (m) in expectation. Yet, the performance of this pattern is below that of well-engineered schedulers, which eschew theoretical guarantees for practical efficiency. We investigate whether it is possible to design and implement a Multi-Queue-based task scheduler that is both highly-efficient and has analytical guarantees. We propose a new variant called the Stealing Multi-Queue (SMQ), a cache-efficient variant of the Multi-Queue, which leverages both queue affinity---each thread has a local queue, from which tasks are usually removed; but, with some probability, threads also attempt to steal higher-priority tasks from the other queues---and task batching, that is, the processing of several tasks in a single insert / remove step. These ideas are well-known for task scheduling without priorities; our theoretical contribution is showing that, despite relaxations, this design can still provide rank guarantees, which in turn implies bounds on total work performed. We provide a general SMQ implementation which can surpass state-of-the-art schedulers such as OBIM and PMOD in terms of performance on popular graph-processing benchmarks. Notably, the performance improvement comes mainly from the superior rank guarantees provided by our scheduler, confirming that analytically-reasoned approaches can still provide performance improvements for priority task scheduling.}, author = {Postnikova, Anastasiia and Koval, Nikita and Nadiradze, Giorgi and Alistarh, Dan-Adrian}, booktitle = {Proceedings of the 27th ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming}, isbn = {9781450392044}, location = {Seoul, Republic of Korea}, pages = {353--367}, publisher = {Association for Computing Machinery}, title = {{Multi-queues can be state-of-the-art priority schedulers}}, doi = {10.1145/3503221.3508432}, year = {2022}, } @inproceedings{11181, abstract = {To maximize the performance of concurrent data structures, researchers have often turned to highly complex fine-grained techniques, resulting in efficient and elegant algorithms, which can however be often difficult to understand and prove correct. While simpler techniques exist, such as transactional memory, they can have limited performance or portability relative to their fine-grained counterparts. Approaches at both ends of this complexity-performance spectrum have been extensively explored, but relatively less is known about the middle ground: approaches that are willing to sacrifice some performance for simplicity, while remaining competitive with state-of-the-art handcrafted designs. In this paper, we explore this middle ground, and present PathCAS, a primitive that combines ideas from multi-word CAS (KCAS) and transactional memory approaches, while carefully avoiding overhead. We show how PathCAS can be used to implement efficient search data structures relatively simply, using an internal binary search tree as an example, then extending this to an AVL tree. Our best implementations outperform many handcrafted search trees: in search-heavy workloads, it rivals the BCCO tree [5], the fastest known concurrent binary tree in terms of search performance [3]. Our results suggest that PathCAS can yield concurrent data structures that are relatively easy to build and prove correct, while offering surprisingly high performance.}, author = {Brown, Trevor A and Sigouin, William and Alistarh, Dan-Adrian}, booktitle = {Proceedings of the 27th ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming}, isbn = {9781450392044}, location = {Seoul, Republic of Korea}, pages = {385--399}, publisher = {Association for Computing Machinery}, title = {{PathCAS: An efficient middle ground for concurrent search data structures}}, doi = {10.1145/3503221.3508410}, year = {2022}, } @inproceedings{11183, abstract = {Subgraph detection has recently been one of the most studied problems in the CONGEST model of distributed computing. In this work, we study the distributed complexity of problems closely related to subgraph detection, mainly focusing on induced subgraph detection. The main line of this work presents lower bounds and parameterized algorithms w.r.t structural parameters of the input graph: - On general graphs, we give unconditional lower bounds for induced detection of cycles and patterns of treewidth 2 in CONGEST. Moreover, by adapting reductions from centralized parameterized complexity, we prove lower bounds in CONGEST for detecting patterns with a 4-clique, and for induced path detection conditional on the hardness of triangle detection in the congested clique. - On graphs of bounded degeneracy, we show that induced paths can be detected fast in CONGEST using techniques from parameterized algorithms, while detecting cycles and patterns of treewidth 2 is hard. - On graphs of bounded vertex cover number, we show that induced subgraph detection is easy in CONGEST for any pattern graph. More specifically, we adapt a centralized parameterized algorithm for a more general maximum common induced subgraph detection problem to the distributed setting. In addition to these induced subgraph detection results, we study various related problems in the CONGEST and congested clique models, including for multicolored versions of subgraph-detection-like problems.}, author = {Nikabadi, Amir and Korhonen, Janne}, booktitle = {25th International Conference on Principles of Distributed Systems}, editor = {Bramas, Quentin and Gramoli, Vincent and Milani, Alessia}, isbn = {9783959772198}, issn = {1868-8969}, location = {Strasbourg, France}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{Beyond distributed subgraph detection: Induced subgraphs, multicolored problems and graph parameters}}, doi = {10.4230/LIPIcs.OPODIS.2021.15}, volume = {217}, year = {2022}, } @inproceedings{11184, abstract = {Let G be a graph on n nodes. In the stochastic population protocol model, a collection of n indistinguishable, resource-limited nodes collectively solve tasks via pairwise interactions. In each interaction, two randomly chosen neighbors first read each other’s states, and then update their local states. A rich line of research has established tight upper and lower bounds on the complexity of fundamental tasks, such as majority and leader election, in this model, when G is a clique. Specifically, in the clique, these tasks can be solved fast, i.e., in n polylog n pairwise interactions, with high probability, using at most polylog n states per node. In this work, we consider the more general setting where G is an arbitrary regular graph, and present a technique for simulating protocols designed for fully-connected networks in any connected regular graph. Our main result is a simulation that is efficient on many interesting graph families: roughly, the simulation overhead is polylogarithmic in the number of nodes, and quadratic in the conductance of the graph. As a sample application, we show that, in any regular graph with conductance φ, both leader election and exact majority can be solved in φ^{-2} ⋅ n polylog n pairwise interactions, with high probability, using at most φ^{-2} ⋅ polylog n states per node. This shows that there are fast and space-efficient population protocols for leader election and exact majority on graphs with good expansion properties. We believe our results will prove generally useful, as they allow efficient technology transfer between the well-mixed (clique) case, and the under-explored spatial setting.}, author = {Alistarh, Dan-Adrian and Gelashvili, Rati and Rybicki, Joel}, booktitle = {25th International Conference on Principles of Distributed Systems}, editor = {Bramas, Quentin and Gramoli, Vincent and Milani, Alessia}, isbn = {9783959772198}, issn = {1868-8969}, location = {Strasbourg, France}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{Fast graphical population protocols}}, doi = {10.4230/LIPIcs.OPODIS.2021.14}, volume = {217}, year = {2022}, } @inproceedings{11185, abstract = {Bundling crossings is a strategy which can enhance the readability of graph drawings. In this paper we consider bundlings for families of pseudosegments, i.e., simple curves such that any two have share at most one point at which they cross. Our main result is that there is a polynomial-time algorithm to compute an 8-approximation of the bundled crossing number of such instances (up to adding a term depending on the facial structure). This 8-approximation also holds for bundlings of good drawings of graphs. In the special case of circular drawings the approximation factor is 8 (no extra term), this improves upon the 10-approximation of Fink et al. [6]. We also show how to compute a 92-approximation when the intersection graph of the pseudosegments is bipartite.}, author = {Arroyo Guevara, Alan M and Felsner, Stefan}, booktitle = {WALCOM 2022: Algorithms and Computation}, isbn = {9783030967307}, issn = {1611-3349}, location = {Jember, Indonesia}, pages = {383--395}, publisher = {Springer Nature}, title = {{Approximating the bundled crossing number}}, doi = {10.1007/978-3-030-96731-4_31}, volume = {13174}, year = {2022}, } @article{11186, abstract = {In this note, we study large deviations of the number 𝐍 of intercalates ( 2×2 combinatorial subsquares which are themselves Latin squares) in a random 𝑛×𝑛 Latin square. In particular, for constant 𝛿>0 we prove that exp(−𝑂(𝑛2log𝑛))⩽Pr(𝐍⩽(1−𝛿)𝑛2/4)⩽exp(−Ω(𝑛2)) and exp(−𝑂(𝑛4/3(log𝑛)))⩽Pr(𝐍⩾(1+𝛿)𝑛2/4)⩽exp(−Ω(𝑛4/3(log𝑛)2/3)) . As a consequence, we deduce that a typical order- 𝑛 Latin square has (1+𝑜(1))𝑛2/4 intercalates, matching a lower bound due to Kwan and Sudakov and resolving an old conjecture of McKay and Wanless.}, author = {Kwan, Matthew Alan and Sah, Ashwin and Sawhney, Mehtaab}, issn = {1469-2120}, journal = {Bulletin of the London Mathematical Society}, number = {4}, pages = {1420--1438}, publisher = {Wiley}, title = {{Large deviations in random latin squares}}, doi = {10.1112/blms.12638}, volume = {54}, year = {2022}, } @article{11187, abstract = {During the COVID-19 pandemic, genomics and bioinformatics have emerged as essential public health tools. The genomic data acquired using these methods have supported the global health response, facilitated the development of testing methods and allowed the timely tracking of novel SARS-CoV-2 variants. Yet the virtually unlimited potential for rapid generation and analysis of genomic data is also coupled with unique technical, scientific and organizational challenges. Here, we discuss the application of genomic and computational methods for efficient data-driven COVID-19 response, the advantages of the democratization of viral sequencing around the world and the challenges associated with viral genome data collection and processing.}, author = {Knyazev, Sergey and Chhugani, Karishma and Sarwal, Varuni and Ayyala, Ram and Singh, Harman and Karthikeyan, Smruthi and Deshpande, Dhrithi and Baykal, Pelin Icer and Comarova, Zoia and Lu, Angela and Porozov, Yuri and Vasylyeva, Tetyana I. and Wertheim, Joel O. and Tierney, Braden T. and Chiu, Charles Y. and Sun, Ren and Wu, Aiping and Abedalthagafi, Malak S. and Pak, Victoria M. and Nagaraj, Shivashankar H. and Smith, Adam L. and Skums, Pavel and Pasaniuc, Bogdan and Komissarov, Andrey and Mason, Christopher E. and Bortz, Eric and Lemey, Philippe and Kondrashov, Fyodor and Beerenwinkel, Niko and Lam, Tommy Tsan Yuk and Wu, Nicholas C. and Zelikovsky, Alex and Knight, Rob and Crandall, Keith A. and Mangul, Serghei}, issn = {1548-7105}, journal = {Nature Methods}, number = {4}, pages = {374--380}, publisher = {Springer Nature}, title = {{Unlocking capacities of genomics for the COVID-19 response and future pandemics}}, doi = {10.1038/s41592-022-01444-z}, volume = {19}, year = {2022}, } @misc{11321, abstract = {Here are the research data underlying the publication "Effects of fine-scale population structure on the distribution of heterozygosity in a long-term study of Antirrhinum majus" Further information are summed up in the README document. }, author = {Surendranadh, Parvathy and Arathoon, Louise S and Baskett, Carina and Field, David and Pickup, Melinda and Barton, Nicholas H}, publisher = {Institute of Science and Technology Austria}, title = {{Effects of fine-scale population structure on the distribution of heterozygosity in a long-term study of Antirrhinum majus}}, doi = {10.15479/at:ista:11321}, year = {2022}, } @article{11330, abstract = {In this article we study the noncommutative transport distance introduced by Carlen and Maas and its entropic regularization defined by Becker and Li. We prove a duality formula that can be understood as a quantum version of the dual Benamou–Brenier formulation of the Wasserstein distance in terms of subsolutions of a Hamilton–Jacobi–Bellmann equation.}, author = {Wirth, Melchior}, issn = {1572-9613}, journal = {Journal of Statistical Physics}, number = {2}, publisher = {Springer Nature}, title = {{A dual formula for the noncommutative transport distance}}, doi = {10.1007/s10955-022-02911-9}, volume = {187}, year = {2022}, } @inproceedings{11331, abstract = {We propose separating the task of reliable transaction dissemination from transaction ordering, to enable high-performance Byzantine fault-tolerant quorum-based consensus. We design and evaluate a mempool protocol, Narwhal, specializing in high-throughput reliable dissemination and storage of causal histories of transactions. Narwhal tolerates an asynchronous network and maintains high performance despite failures. Narwhal is designed to easily scale-out using multiple workers at each validator, and we demonstrate that there is no foreseeable limit to the throughput we can achieve. Composing Narwhal with a partially synchronous consensus protocol (Narwhal-HotStuff) yields significantly better throughput even in the presence of faults or intermittent loss of liveness due to asynchrony. However, loss of liveness can result in higher latency. To achieve overall good performance when faults occur we design Tusk, a zero-message overhead asynchronous consensus protocol, to work with Narwhal. We demonstrate its high performance under a variety of configurations and faults. As a summary of results, on a WAN, Narwhal-Hotstuff achieves over 130,000 tx/sec at less than 2-sec latency compared with 1,800 tx/sec at 1-sec latency for Hotstuff. Additional workers increase throughput linearly to 600,000 tx/sec without any latency increase. Tusk achieves 160,000 tx/sec with about 3 seconds latency. Under faults, both protocols maintain high throughput, but Narwhal-HotStuff suffers from increased latency.}, author = {Danezis, George and Kokoris Kogias, Eleftherios and Sonnino, Alberto and Spiegelman, Alexander}, booktitle = {Proceedings of the 17th European Conference on Computer Systems}, isbn = {9781450391627}, location = {Rennes, France}, pages = {34--50}, publisher = {Association for Computing Machinery}, title = {{Narwhal and Tusk: A DAG-based mempool and efficient BFT consensus}}, doi = {10.1145/3492321.3519594}, year = {2022}, } @article{11332, abstract = {We show that the fluctuations of the largest eigenvalue of a real symmetric or complex Hermitian Wigner matrix of size N converge to the Tracy–Widom laws at a rate O(N^{-1/3+\omega }), as N tends to infinity. For Wigner matrices this improves the previous rate O(N^{-2/9+\omega }) obtained by Bourgade (J Eur Math Soc, 2021) for generalized Wigner matrices. Our result follows from a Green function comparison theorem, originally introduced by Erdős et al. (Adv Math 229(3):1435–1515, 2012) to prove edge universality, on a finer spectral parameter scale with improved error estimates. The proof relies on the continuous Green function flow induced by a matrix-valued Ornstein–Uhlenbeck process. Precise estimates on leading contributions from the third and fourth order moments of the matrix entries are obtained using iterative cumulant expansions and recursive comparisons for correlation functions, along with uniform convergence estimates for correlation kernels of the Gaussian invariant ensembles.}, author = {Schnelli, Kevin and Xu, Yuanyuan}, issn = {1432-0916}, journal = {Communications in Mathematical Physics}, pages = {839--907}, publisher = {Springer Nature}, title = {{Convergence rate to the Tracy–Widom laws for the largest Eigenvalue of Wigner matrices}}, doi = {10.1007/s00220-022-04377-y}, volume = {393}, year = {2022}, } @article{11334, abstract = {Hybridization is a common evolutionary process with multiple possible outcomes. In vertebrates, interspecific hybridization has repeatedly generated parthenogenetic hybrid species. However, it is unknown whether the generation of parthenogenetic hybrids is a rare outcome of frequent hybridization between sexual species within a genus or the typical outcome of rare hybridization events. Darevskia is a genus of rock lizards with both hybrid parthenogenetic and sexual species. Using capture sequencing, we estimate phylogenetic relationships and gene flow among the sexual species, to determine how introgressive hybridization relates to the origins of parthenogenetic hybrids. We find evidence for widespread hybridization with gene flow, both between recently diverged species and deep branches. Surprisingly, we find no signal of gene flow between parental species of the parthenogenetic hybrids, suggesting that the parental pairs were either reproductively or geographically isolated early in their divergence. The generation of parthenogenetic hybrids in Darevskia is, then, a rare outcome of the total occurrence of hybridization within the genus, but the typical outcome when specific species pairs hybridize. Our results question the conventional view that parthenogenetic lineages are generated by hybridization in a window of divergence. Instead, they suggest that some lineages possess specific properties that underpin successful parthenogenetic reproduction.}, author = {Freitas, Susana and Westram, Anja M and Schwander, Tanja and Arakelyan, Marine and Ilgaz, Çetin and Kumlutas, Yusuf and Harris, David James and Carretero, Miguel A. and Butlin, Roger K.}, issn = {1558-5646}, journal = {Evolution}, number = {5}, pages = {899--914}, publisher = {Wiley}, title = {{Parthenogenesis in Darevskia lizards: A rare outcome of common hybridization, not a common outcome of rare hybridization}}, doi = {10.1111/evo.14462}, volume = {76}, year = {2022}, } @article{11336, abstract = {The generation of a correctly-sized cerebral cortex with all-embracing neuronal and glial cell-type diversity critically depends on faithful radial glial progenitor (RGP) cell proliferation/differentiation programs. Temporal RGP lineage progression is regulated by Polycomb Repressive Complex 2 (PRC2) and loss of PRC2 activity results in severe neurogenesis defects and microcephaly. How PRC2-dependent gene expression instructs RGP lineage progression is unknown. Here we utilize Mosaic Analysis with Double Markers (MADM)-based single cell technology and demonstrate that PRC2 is not cell-autonomously required in neurogenic RGPs but rather acts at the global tissue-wide level. Conversely, cortical astrocyte production and maturation is cell-autonomously controlled by PRC2-dependent transcriptional regulation. We thus reveal highly distinct and sequential PRC2 functions in RGP lineage progression that are dependent on complex interplays between intrinsic and tissue-wide properties. In a broader context our results imply a critical role for the genetic and cellular niche environment in neural stem cell behavior.}, author = {Amberg, Nicole and Pauler, Florian and Streicher, Carmen and Hippenmeyer, Simon}, issn = {2375-2548}, journal = {Science Advances}, number = {44}, publisher = {American Association for the Advancement of Science}, title = {{Tissue-wide genetic and cellular landscape shapes the execution of sequential PRC2 functions in neural stem cell lineage progression}}, doi = {10.1126/sciadv.abq1263}, volume = {8}, year = {2022}, } @article{11337, abstract = {Nonanalytic points in the return probability of a quantum state as a function of time, known as dynamical quantum phase transitions (DQPTs), have received great attention in recent years, but the understanding of their mechanism is still incomplete. In our recent work [Phys. Rev. Lett. 126, 040602 (2021)], we demonstrated that one-dimensional DQPTs can be produced by two distinct mechanisms, namely semiclassical precession and entanglement generation, leading to the definition of precession (pDQPTs) and entanglement (eDQPTs) dynamical quantum phase transitions. In this manuscript, we extend and investigate the notion of p- and eDQPTs in two-dimensional systems by considering semi-infinite ladders of varying width. For square lattices, we find that pDQPTs and eDQPTs persist and are characterized by similar phenomenology as in 1D: pDQPTs are associated with a magnetization sign change and a wide entanglement gap, while eDQPTs correspond to suppressed local observables and avoided crossings in the entanglement spectrum. However, DQPTs show higher sensitivity to the ladder width and other details, challenging the extrapolation to the thermodynamic limit especially for eDQPTs. Moving to honeycomb lattices, we also demonstrate that lattices with an odd number of nearest neighbors give rise to phenomenologies beyond the one-dimensional classification.}, author = {De Nicola, Stefano and Michailidis, Alexios and Serbyn, Maksym}, issn = {2469-9950}, journal = {Physical Review B}, publisher = {American Physical Society}, title = {{Entanglement and precession in two-dimensional dynamical quantum phase transitions}}, doi = {10.1103/PhysRevB.105.165149}, volume = {105}, year = {2022}, } @article{11339, abstract = {The interaction between a cell and its environment shapes fundamental intracellular processes such as cellular metabolism. In most cases growth rate is treated as a proximal metric for understanding the cellular metabolic status. However, changes in growth rate might not reflect metabolic variations in individuals responding to environmental fluctuations. Here we use single-cell microfluidics-microscopy combined with transcriptomics, proteomics and mathematical modelling to quantify the accumulation of glucose within Escherichia coli cells. In contrast to the current consensus, we reveal that environmental conditions which are comparatively unfavourable for growth, where both nutrients and salinity are depleted, increase glucose accumulation rates in individual bacteria and population subsets. We find that these changes in metabolic function are underpinned by variations at the translational and posttranslational level but not at the transcriptional level and are not dictated by changes in cell size. The metabolic response-characteristics identified greatly advance our fundamental understanding of the interactions between bacteria and their environment and have important ramifications when investigating cellular processes where salinity plays an important role.}, author = {Glover, Georgina and Voliotis, Margaritis and Łapińska, Urszula and Invergo, Brandon M. and Soanes, Darren and O’Neill, Paul and Moore, Karen and Nikolic, Nela and Petrov, Peter and Milner, David S. and Roy, Sumita and Heesom, Kate and Richards, Thomas A. and Tsaneva-Atanasova, Krasimira and Pagliara, Stefano}, issn = {2399-3642}, journal = {Communications Biology}, publisher = {Springer Nature}, title = {{Nutrient and salt depletion synergistically boosts glucose metabolism in individual Escherichia coli cells}}, doi = {10.1038/s42003-022-03336-6}, volume = {5}, year = {2022}, } @article{11340, abstract = {Like-charge attraction, driven by ionic correlations, challenges our understanding of electrostatics both in soft and hard matter. For two charged planar surfaces confining counterions and water, we prove that, even at relatively low correlation strength, the relevant physics is the ground-state one, oblivious of fluctuations. Based on this, we derive a simple and accurate interaction pressure that fulfills known exact requirements and can be used as an effective potential. We test this equation against implicit-solvent Monte Carlo simulations and against explicit-solvent simulations of cement and several types of clays. We argue that water destructuring under nanometric confinement drastically reduces dielectric screening, enhancing ionic correlations. Our equation of state at reduced permittivity therefore explains the exotic attractive regime reported for these materials, even in the absence of multivalent counterions.}, author = {Palaia, Ivan and Goyal, Abhay and Del Gado, Emanuela and Šamaj, Ladislav and Trizac, Emmanuel}, issn = {1520-5207}, journal = {Journal of Physical Chemistry B}, number = {16}, pages = {3143--3149}, publisher = {American Chemical Society}, title = {{Like-charge attraction at the nanoscale: Ground-state correlations and water destructuring}}, doi = {10.1021/acs.jpcb.2c00028}, volume = {126}, year = {2022}, } @article{11343, abstract = {Multistable systems are characterized by exhibiting domain coexistence, where each domain accounts for the different equilibrium states. In case these systems are described by vectorial fields, domains can be connected through topological defects. Vortices are one of the most frequent and studied topological defect points. Optical vortices are equally relevant for their fundamental features as beams with topological features and their applications in image processing, telecommunications, optical tweezers, and quantum information. A natural source of optical vortices is the interaction of light beams with matter vortices in liquid crystal cells. The rhythms that govern the emergence of matter vortices due to fluctuations are not established. Here, we investigate the nucleation mechanisms of the matter vortices in liquid crystal cells and establish statistical laws that govern them. Based on a stochastic amplitude equation, the law for the number of nucleated vortices as a function of anisotropy, voltage, and noise level intensity is set. Experimental observations in a nematic liquid crystal cell with homeotropic anchoring and a negative anisotropic dielectric constant under the influence of a transversal electric field show a qualitative agreement with the theoretical findings.}, author = {Aguilera, Esteban and Clerc, Marcel G. and Zambra, Valeska}, issn = {1573-269X}, journal = {Nonlinear Dynamics}, keywords = {Electrical and Electronic Engineering, Applied Mathematics, Mechanical Engineering, Ocean Engineering, Aerospace Engineering, Control and Systems Engineering}, pages = {3209--3218}, publisher = {Springer Nature}, title = {{Vortices nucleation by inherent fluctuations in nematic liquid crystal cells}}, doi = {10.1007/s11071-022-07396-5}, volume = {108}, year = {2022}, } @article{11351, abstract = {One hallmark of plant cells is their cell wall. They protect cells against the environment and high turgor and mediate morphogenesis through the dynamics of their mechanical and chemical properties. The walls are a complex polysaccharidic structure. Although their biochemical composition is well known, how the different components organize in the volume of the cell wall and interact with each other is not well understood and yet is key to the wall’s mechanical properties. To investigate the ultrastructure of the plant cell wall, we imaged the walls of onion (Allium cepa) bulbs in a near-native state via cryo-focused ion beam milling (cryo-FIB milling) and cryo-electron tomography (cryo-ET). This allowed the high-resolution visualization of cellulose fibers in situ. We reveal the coexistence of dense fiber fields bathed in a reticulated matrix we termed “meshing,” which is more abundant at the inner surface of the cell wall. The fibers adopted a regular bimodal angular distribution at all depths in the cell wall and bundled according to their orientation, creating layers within the cell wall. Concomitantly, employing homogalacturonan (HG)-specific enzymatic digestion, we observed changes in the meshing, suggesting that it is—at least in part—composed of HG pectins. We propose the following model for the construction of the abaxial epidermal primary cell wall: the cell deposits successive layers of cellulose fibers at −45° and +45° relative to the cell’s long axis and secretes the surrounding HG-rich meshing proximal to the plasma membrane, which then migrates to more distal regions of the cell wall.}, author = {Nicolas, William J. and Fäßler, Florian and Dutka, Przemysław and Schur, Florian KM and Jensen, Grant and Meyerowitz, Elliot}, issn = {0960-9822}, journal = {Current Biology}, keywords = {General Agricultural and Biological Sciences, General Biochemistry, Genetics and Molecular Biology}, number = {11}, pages = {P2375--2389}, publisher = {Elsevier}, title = {{Cryo-electron tomography of the onion cell wall shows bimodally oriented cellulose fibers and reticulated homogalacturonan networks}}, doi = {10.1016/j.cub.2022.04.024}, volume = {32}, year = {2022}, }