@article{12051, abstract = {Transcription of the ribosomal RNA precursor by RNA polymerase (Pol) I is a major determinant of cellular growth, and dysregulation is observed in many cancer types. Here, we present the purification of human Pol I from cells carrying a genomic GFP fusion on the largest subunit allowing the structural and functional analysis of the enzyme across species. In contrast to yeast, human Pol I carries a single-subunit stalk, and in vitro transcription indicates a reduced proofreading activity. Determination of the human Pol I cryo-EM reconstruction in a close-to-native state rationalizes the effects of disease-associated mutations and uncovers an additional domain that is built into the sequence of Pol I subunit RPA1. This “dock II” domain resembles a truncated HMG box incapable of DNA binding which may serve as a downstream transcription factor–binding platform in metazoans. Biochemical analysis, in situ modelling, and ChIP data indicate that Topoisomerase 2a can be recruited to Pol I via the domain and cooperates with the HMG box domain–containing factor UBF. These adaptations of the metazoan Pol I transcription system may allow efficient release of positive DNA supercoils accumulating downstream of the transcription bubble.}, author = {Daiß, Julia L and Pilsl, Michael and Straub, Kristina and Bleckmann, Andrea and Höcherl, Mona and Heiss, Florian B and Abascal-Palacios, Guillermo and Ramsay, Ewan P and Tluckova, Katarina and Mars, Jean-Clement and Fürtges, Torben and Bruckmann, Astrid and Rudack, Till and Bernecky, Carrie A and Lamour, Valérie and Panov, Konstantin and Vannini, Alessandro and Moss, Tom and Engel, Christoph}, issn = {2575-1077}, journal = {Life Science Alliance}, keywords = {Health, Toxicology and Mutagenesis, Plant Science, Biochemistry, Genetics and Molecular Biology (miscellaneous), Ecology}, number = {11}, publisher = {Life Science Alliance}, title = {{The human RNA polymerase I structure reveals an HMG-like docking domain specific to metazoans}}, doi = {10.26508/lsa.202201568}, volume = {5}, year = {2022}, } @article{12052, abstract = {Directionality in the intercellular transport of the plant hormone auxin is determined by polar plasma membrane localization of PIN-FORMED (PIN) auxin transport proteins. However, apart from PIN phosphorylation at conserved motifs, no further determinants explicitly controlling polar PIN sorting decisions have been identified. Here we present Arabidopsis WAVY GROWTH 3 (WAV3) and closely related RING-finger E3 ubiquitin ligases, whose loss-of-function mutants show a striking apical-to-basal polarity switch in PIN2 localization in root meristem cells. WAV3 E3 ligases function as essential determinants for PIN polarity, acting independently from PINOID/WAG-dependent PIN phosphorylation. They antagonize ectopic deposition of de novo synthesized PIN proteins already immediately following completion of cell division, presumably via preventing PIN sorting into basal, ARF GEF-mediated trafficking. Our findings reveal an involvement of E3 ligases in the selective targeting of apically localized PINs in higher plants.}, author = {Konstantinova, N and Hörmayer, Lukas and Glanc, Matous and Keshkeih, R and Tan, Shutang and Di Donato, M and Retzer, K and Moulinier-Anzola, J and Schwihla, M and Korbei, B and Geisler, M and Friml, Jiří and Luschnig, C}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{WAVY GROWTH Arabidopsis E3 ubiquitin ligases affect apical PIN sorting decisions}}, doi = {10.1038/s41467-022-32888-8}, volume = {13}, year = {2022}, } @article{12053, abstract = {Strigolactones (SLs) are a class of phytohormones that regulate plant shoot branching and adventitious root development. However, little is known regarding the role of SLs in controlling the behavior of the smallest unit of the organism, the single cell. Here, taking advantage of a classic single-cell model offered by the cotton (Gossypium hirsutum) fiber cell, we show that SLs, whose biosynthesis is fine-tuned by gibberellins (GAs), positively regulate cell elongation and cell wall thickness by promoting the biosynthesis of very-long-chain fatty acids (VLCFAs) and cellulose, respectively. Furthermore, we identified two layers of transcription factors (TFs) involved in the hierarchical regulation of this GA-SL crosstalk. The top-layer TF GROWTH-REGULATING FACTOR 4 (GhGRF4) directly activates expression of the SL biosynthetic gene DWARF27 (D27) to increase SL accumulation in fiber cells and GAs induce GhGRF4 expression. SLs induce the expression of four second-layer TF genes (GhNAC100-2, GhBLH51, GhGT2, and GhB9SHZ1), which transmit SL signals downstream to two ketoacyl-CoA synthase genes (KCS) and three cellulose synthase (CesA) genes by directly activating their transcription. Finally, the KCS and CesA enzymes catalyze the biosynthesis of very long chain fatty acids and cellulose, respectively, to regulate development of high-grade cotton fibers. In addition to providing a theoretical basis for cotton fiber improvement, our results shed light on SL signaling in plant development at the single-cell level.}, author = {Tian, Z and Zhang, Yuzhou and Zhu, L and Jiang, B and Wang, H and Gao, R and Friml, Jiří and Xiao, G}, issn = {1532-298X}, journal = {The Plant Cell}, number = {12}, pages = {4816--4839}, publisher = {Oxford University Press}, title = {{Strigolactones act downstream of gibberellins to regulate fiber cell elongation and cell wall thickness in cotton (Gossypium hirsutum)}}, doi = {10.1093/plcell/koac270}, volume = {34}, year = {2022}, } @article{12054, abstract = {Polar auxin transport is unique to plants and coordinates their growth and development1,2. The PIN-FORMED (PIN) auxin transporters exhibit highly asymmetrical localizations at the plasma membrane and drive polar auxin transport3,4; however, their structures and transport mechanisms remain largely unknown. Here, we report three inward-facing conformation structures of Arabidopsis thaliana PIN1: the apo state, bound to the natural auxin indole-3-acetic acid (IAA), and in complex with the polar auxin transport inhibitor N-1-naphthylphthalamic acid (NPA). The transmembrane domain of PIN1 shares a conserved NhaA fold5. In the substrate-bound structure, IAA is coordinated by both hydrophobic stacking and hydrogen bonding. NPA competes with IAA for the same site at the intracellular pocket, but with a much higher affinity. These findings inform our understanding of the substrate recognition and transport mechanisms of PINs and set up a framework for future research on directional auxin transport, one of the most crucial processes underlying plant development.}, author = {Yang, Z and Xia, J and Hong, J and Zhang, C and Wei, H and Ying, W and Sun, C and Sun, L and Mao, Y and Gao, Y and Tan, S and Friml, Jiří and Li, D and Liu, X and Sun, L}, issn = {1476-4687}, journal = {Nature}, number = {7927}, pages = {611--615}, publisher = {Springer Nature}, title = {{Structural insights into auxin recognition and efflux by Arabidopsis PIN1}}, doi = {10.1038/s41586-022-05143-9}, volume = {609}, year = {2022}, } @article{12065, abstract = {Capacity, rate performance, and cycle life of aprotic Li–O2 batteries critically depend on reversible electrodeposition of Li2O2. Current understanding states surface-adsorbed versus solvated LiO2 controls Li2O2 growth as surface film or as large particles. Herein, we show that Li2O2 forms across a wide range of electrolytes, carbons, and current densities as particles via solution-mediated LiO2 disproportionation, bringing into question the prevalence of any surface growth under practical conditions. We describe a unified O2 reduction mechanism, which can explain all found capacity relations and Li2O2 morphologies with exclusive solution discharge. Determining particle morphology and achievable capacities are species mobilities, true areal rate, and the degree of LiO2 association in solution. Capacity is conclusively limited by mass transport through the tortuous Li2O2 rather than electron transport through a passivating Li2O2 film. Provided that species mobilities and surface growth are high, high capacities are also achieved with weakly solvating electrolytes, which were previously considered prototypical for low capacity via surface growth.}, author = {Prehal, Christian and Mondal, Soumyadip and Lovicar, Ludek and Freunberger, Stefan Alexander}, issn = {2380-8195}, journal = {ACS Energy Letters}, number = {9}, pages = {3112--3119}, publisher = {American Chemical Society}, title = {{Exclusive solution discharge in Li-O₂ batteries?}}, doi = {10.1021/acsenergylett.2c01711}, volume = {7}, year = {2022}, } @phdthesis{12072, abstract = {In this thesis, we study two of the most important questions in Arithmetic geometry: that of the existence and density of solutions to Diophantine equations. In order for a Diophantine equation to have any solutions over the rational numbers, it must have solutions everywhere locally, i.e., over R and over Qp for every prime p. The converse, called the Hasse principle, is known to fail in general. However, it is still a central question in Arithmetic geometry to determine for which varieties the Hasse principle does hold. In this work, we establish the Hasse principle for a wide new family of varieties of the form f(t) = NK/Q(x) ̸= 0, where f is a polynomial with integer coefficients and NK/Q denotes the norm form associated to a number field K. Our results cover products of arbitrarily many linear, quadratic or cubic factors, and generalise an argument of Irving [69], which makes use of the beta sieve of Rosser and Iwaniec. We also demonstrate how our main sieve results can be applied to treat new cases of a conjecture of Harpaz and Wittenberg on locally split values of polynomials over number fields, and discuss consequences for rational points in fibrations. In the second question, about the density of solutions, one defines a height function and seeks to estimate asymptotically the number of points of height bounded by B as B → ∞. Traditionally, one either counts rational points, or integral points with respect to a suitable model. However, in this thesis, we study an emerging area of interest in Arithmetic geometry known as Campana points, which in some sense interpolate between rational and integral points. More precisely, we count the number of nonzero integers z1, z2, z3 such that gcd(z1, z2, z3) = 1, and z1, z2, z3, z1 + z2 + z3 are all squareful and bounded by B. Using the circle method, we obtain an asymptotic formula which agrees in the power of B and log B with a bold new generalisation of Manin’s conjecture to the setting of Campana points, recently formulated by Pieropan, Smeets, Tanimoto and Várilly-Alvarado [96]. However, in this thesis we also provide the first known counterexamples to leading constant predicted by their conjecture. }, author = {Shute, Alec L}, isbn = {978-3-99078-023-7}, issn = {2663-337X}, pages = {208}, publisher = {Institute of Science and Technology Austria}, title = {{Existence and density problems in Diophantine geometry: From norm forms to Campana points}}, doi = {10.15479/at:ista:12072}, year = {2022}, } @article{12079, abstract = {We extend the recent rigorous convergence result of Abels and Moser (SIAM J Math Anal 54(1):114–172, 2022. https://doi.org/10.1137/21M1424925) concerning convergence rates for solutions of the Allen–Cahn equation with a nonlinear Robin boundary condition towards evolution by mean curvature flow with constant contact angle. More precisely, in the present work we manage to remove the perturbative assumption on the contact angle being close to 90∘. We establish under usual double-well type assumptions on the potential and for a certain class of boundary energy densities the sub-optimal convergence rate of order ε12 for general contact angles α∈(0,π). For a very specific form of the boundary energy density, we even obtain from our methods a sharp convergence rate of order ε; again for general contact angles α∈(0,π). Our proof deviates from the popular strategy based on rigorous asymptotic expansions and stability estimates for the linearized Allen–Cahn operator. Instead, we follow the recent approach by Fischer et al. (SIAM J Math Anal 52(6):6222–6233, 2020. https://doi.org/10.1137/20M1322182), thus relying on a relative entropy technique. We develop a careful adaptation of their approach in order to encode the constant contact angle condition. In fact, we perform this task at the level of the notion of gradient flow calibrations. This concept was recently introduced in the context of weak-strong uniqueness for multiphase mean curvature flow by Fischer et al. (arXiv:2003.05478v2).}, author = {Hensel, Sebastian and Moser, Maximilian}, issn = {1432-0835}, journal = {Calculus of Variations and Partial Differential Equations}, number = {6}, publisher = {Springer Nature}, title = {{Convergence rates for the Allen–Cahn equation with boundary contact energy: The non-perturbative regime}}, doi = {10.1007/s00526-022-02307-3}, volume = {61}, year = {2022}, } @article{12080, abstract = {Endocytosis is a multistep process involving the sequential recruitment and action of numerous proteins. This process can be divided into two phases: an early phase, in which sites of endocytosis are formed, and a late phase in which clathrin-coated vesicles are formed and internalized into the cytosol, but how these phases link to each other remains unclear. In this study, we demonstrate that anchoring the yeast Eps15-like protein Pan1p to the peroxisome triggers most of the events occurring during the late phase at the peroxisome. At this ectopic location, Pan1p recruits most proteins that function in the late phases—including actin nucleation promoting factors—and then initiates actin polymerization. Pan1p also recruited Prk1 kinase and actin depolymerizing factors, thereby triggering disassembly immediately after actin assembly and inducing dissociation of endocytic proteins from the peroxisome. These observations suggest that Pan1p is a key regulator for initiating, processing, and completing the late phase of endocytosis.}, author = {Enshoji, Mariko and Miyano, Yoshiko and Yoshida, Nao and Nagano, Makoto and Watanabe, Minami and Kunihiro, Mayumi and Siekhaus, Daria E and Toshima, Junko Y. and Toshima, Jiro}, issn = {1540-8140}, journal = {Journal of Cell Biology}, number = {10}, publisher = {Rockefeller University Press}, title = {{Eps15/Pan1p is a master regulator of the late stages of the endocytic pathway}}, doi = {10.1083/jcb.202112138}, volume = {221}, year = {2022}, } @article{12081, abstract = {Selection accumulates information in the genome—it guides stochastically evolving populations toward states (genotype frequencies) that would be unlikely under neutrality. This can be quantified as the Kullback–Leibler (KL) divergence between the actual distribution of genotype frequencies and the corresponding neutral distribution. First, we show that this population-level information sets an upper bound on the information at the level of genotype and phenotype, limiting how precisely they can be specified by selection. Next, we study how the accumulation and maintenance of information is limited by the cost of selection, measured as the genetic load or the relative fitness variance, both of which we connect to the control-theoretic KL cost of control. The information accumulation rate is upper bounded by the population size times the cost of selection. This bound is very general, and applies across models (Wright–Fisher, Moran, diffusion) and to arbitrary forms of selection, mutation, and recombination. Finally, the cost of maintaining information depends on how it is encoded: Specifying a single allele out of two is expensive, but one bit encoded among many weakly specified loci (as in a polygenic trait) is cheap.}, author = {Hledik, Michal and Barton, Nicholas H and Tkačik, Gašper}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences}, number = {36}, publisher = {Proceedings of the National Academy of Sciences}, title = {{Accumulation and maintenance of information in evolution}}, doi = {10.1073/pnas.2123152119}, volume = {119}, year = {2022}, } @article{12082, abstract = {Proximity-dependent protein labeling provides a powerful in vivo strategy to characterize the interactomes of specific proteins. We previously optimized a proximity labeling protocol for Caenorhabditis elegans using the highly active biotin ligase TurboID. A significant constraint on the sensitivity of TurboID is the presence of abundant endogenously biotinylated proteins that take up bandwidth in the mass spectrometer, notably carboxylases that use biotin as a cofactor. In C. elegans, these comprise POD-2/acetyl-CoA carboxylase alpha, PCCA-1/propionyl-CoA carboxylase alpha, PYC-1/pyruvate carboxylase, and MCCC-1/methylcrotonyl-CoA carboxylase alpha. Here, we developed ways to remove these carboxylases prior to streptavidin purification and mass spectrometry by engineering their corresponding genes to add a C-terminal His10 tag. This allows us to deplete them from C. elegans lysates using immobilized metal affinity chromatography. To demonstrate the method's efficacy, we use it to expand the interactome map of the presynaptic active zone protein ELKS-1. We identify many known active zone proteins, including UNC-10/RIM, SYD-2/liprin-alpha, SAD-1/BRSK1, CLA-1/CLArinet, C16E9.2/Sentryn, as well as previously uncharacterized potentially synaptic proteins such as the ortholog of human angiomotin, F59C12.3 and the uncharacterized protein R148.3. Our approach provides a quick and inexpensive solution to a common contaminant problem in biotin-dependent proximity labeling. The approach may be applicable to other model organisms and will enable deeper and more complete analysis of interactors for proteins of interest.}, author = {Artan, Murat and Hartl, Markus and Chen, Weiqiang and De Bono, Mario}, issn = {1083-351X}, journal = {Journal of Biological Chemistry}, number = {9}, publisher = {Elsevier}, title = {{Depletion of endogenously biotinylated carboxylases enhances the sensitivity of TurboID-mediated proximity labeling in Caenorhabditis elegans}}, doi = {10.1016/j.jbc.2022.102343}, volume = {298}, year = {2022}, } @article{12083, abstract = {We consider the many-body time evolution of weakly interacting bosons in the mean field regime for initial coherent states. We show that bounded k-particle operators, corresponding to dependent random variables, satisfy both a law of large numbers and a central limit theorem.}, author = {Rademacher, Simone Anna Elvira}, issn = {0022-2488}, journal = {Journal of Mathematical Physics}, number = {8}, publisher = {AIP Publishing}, title = {{Dependent random variables in quantum dynamics}}, doi = {10.1063/5.0086712}, volume = {63}, year = {2022}, } @article{12084, abstract = {Neuronal networks encode information through patterns of activity that define the networks’ function. The neurons’ activity relies on specific connectivity structures, yet the link between structure and function is not fully understood. Here, we tackle this structure-function problem with a new conceptual approach. Instead of manipulating the connectivity directly, we focus on upper triangular matrices, which represent the network dynamics in a given orthonormal basis obtained by the Schur decomposition. This abstraction allows us to independently manipulate the eigenspectrum and feedforward structures of a connectivity matrix. Using this method, we describe a diverse repertoire of non-normal transient amplification, and to complement the analysis of the dynamical regimes, we quantify the geometry of output trajectories through the effective rank of both the eigenvector and the dynamics matrices. Counter-intuitively, we find that shrinking the eigenspectrum’s imaginary distribution leads to highly amplifying regimes in linear and long-lasting dynamics in nonlinear networks. We also find a trade-off between amplification and dimensionality of neuronal dynamics, i.e., trajectories in neuronal state-space. Networks that can amplify a large number of orthogonal initial conditions produce neuronal trajectories that lie in the same subspace of the neuronal state-space. Finally, we examine networks of excitatory and inhibitory neurons. We find that the strength of global inhibition is directly linked with the amplitude of amplification, such that weakening inhibitory weights also decreases amplification, and that the eigenspectrum’s imaginary distribution grows with an increase in the ratio between excitatory-to-inhibitory and excitatory-to-excitatory connectivity strengths. Consequently, the strength of global inhibition reveals itself as a strong signature for amplification and a potential control mechanism to switch dynamical regimes. Our results shed a light on how biological networks, i.e., networks constrained by Dale’s law, may be optimised for specific dynamical regimes.}, author = {Christodoulou, Georgia and Vogels, Tim P and Agnes, Everton J.}, issn = {1553-7358}, journal = {PLoS Computational Biology}, number = {8}, publisher = {Public Library of Science}, title = {{Regimes and mechanisms of transient amplification in abstract and biological neural networks}}, doi = {10.1371/journal.pcbi.1010365}, volume = {18}, year = {2022}, } @article{12085, abstract = {Molecular catch bonds are ubiquitous in biology and essential for processes like leucocyte extravasion1 and cellular mechanosensing2. Unlike normal (slip) bonds, catch bonds strengthen under tension. The current paradigm is that this feature provides ‘strength on demand3’, thus enabling cells to increase rigidity under stress1,4,5,6. However, catch bonds are often weaker than slip bonds because they have cryptic binding sites that are usually buried7,8. Here we show that catch bonds render reconstituted cytoskeletal actin networks stronger than slip bonds, even though the individual bonds are weaker. Simulations show that slip bonds remain trapped in stress-free areas, whereas weak binding allows catch bonds to mitigate crack initiation by moving to high-tension areas. This ‘dissociation on demand’ explains how cells combine mechanical strength with the adaptability required for shape change, and is relevant to diseases where catch bonding is compromised7,9, including focal segmental glomerulosclerosis10 caused by the α-actinin-4 mutant studied here. We surmise that catch bonds are the key to create life-like materials.}, author = {Mulla, Yuval and Avellaneda Sarrió, Mario and Roland, Antoine and Baldauf, Lucia and Jung, Wonyeong and Kim, Taeyoon and Tans, Sander J. and Koenderink, Gijsje H.}, issn = {1476-4660}, journal = {Nature Materials}, number = {9}, pages = {1019--1023}, publisher = {Springer Nature}, title = {{Weak catch bonds make strong networks}}, doi = {10.1038/s41563-022-01288-0}, volume = {21}, year = {2022}, } @inproceedings{12088, abstract = {We present a quantum-enabled microwave-telecom interface with bidirectional conversion efficiencies up to 15% and added input noise quanta as low as 0.16. Moreover, we observe evidence for electro-optic laser cooling and vacuum amplification.}, author = {Sahu, Rishabh and Hease, William J and Rueda Sanchez, Alfredo R and Arnold, Georg M and Qiu, Liu and Fink, Johannes M}, booktitle = {Conference on Lasers and Electro-Optics}, isbn = {9781557528209}, location = {San Jose, CA, United States}, publisher = {Optica Publishing Group}, title = {{Realizing a quantum-enabled interconnect between microwave and telecom light}}, doi = {10.1364/CLEO_QELS.2022.FW4D.4}, year = {2022}, } @inproceedings{12101, abstract = {Spatial games form a widely-studied class of games from biology and physics modeling the evolution of social behavior. Formally, such a game is defined by a square (d by d) payoff matrix M and an undirected graph G. Each vertex of G represents an individual, that initially follows some strategy i ∈ {1,2,…,d}. In each round of the game, every individual plays the matrix game with each of its neighbors: An individual following strategy i meeting a neighbor following strategy j receives a payoff equal to the entry (i,j) of M. Then, each individual updates its strategy to its neighbors' strategy with the highest sum of payoffs, and the next round starts. The basic computational problems consist of reachability between configurations and the average frequency of a strategy. For general spatial games and graphs, these problems are in PSPACE. In this paper, we examine restricted setting: the game is a prisoner’s dilemma; and G is a subgraph of grid. We prove that basic computational problems for spatial games with prisoner’s dilemma on a subgraph of a grid are PSPACE-hard.}, author = {Chatterjee, Krishnendu and Ibsen-Jensen, Rasmus and Jecker, Ismael R and Svoboda, Jakub}, booktitle = {42nd IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science}, isbn = {9783959772617}, issn = {1868-8969}, location = {Madras, India}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{Complexity of spatial games}}, doi = {10.4230/LIPIcs.FSTTCS.2022.11}, volume = {250}, year = {2022}, } @inproceedings{12102, abstract = {Given a Markov chain M = (V, v_0, δ), with state space V and a starting state v_0, and a probability threshold ε, an ε-core is a subset C of states that is left with probability at most ε. More formally, C ⊆ V is an ε-core, iff ℙ[reach (V\C)] ≤ ε. Cores have been applied in a wide variety of verification problems over Markov chains, Markov decision processes, and probabilistic programs, as a means of discarding uninteresting and low-probability parts of a probabilistic system and instead being able to focus on the states that are likely to be encountered in a real-world run. In this work, we focus on the problem of computing a minimal ε-core in a Markov chain. Our contributions include both negative and positive results: (i) We show that the decision problem on the existence of an ε-core of a given size is NP-complete. This solves an open problem posed in [Jan Kretínský and Tobias Meggendorfer, 2020]. We additionally show that the problem remains NP-complete even when limited to acyclic Markov chains with bounded maximal vertex degree; (ii) We provide a polynomial time algorithm for computing a minimal ε-core on Markov chains over control-flow graphs of structured programs. A straightforward combination of our algorithm with standard branch prediction techniques allows one to apply the idea of cores to find a subset of program lines that are left with low probability and then focus any desired static analysis on this core subset.}, author = {Ahmadi, Ali and Chatterjee, Krishnendu and Goharshady, Amir Kafshdar and Meggendorfer, Tobias and Safavi Hemami, Roodabeh and Zikelic, Dorde}, booktitle = {42nd IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science}, isbn = {9783959772617}, issn = {1868-8969}, location = {Madras, India}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{Algorithms and hardness results for computing cores of Markov chains}}, doi = {10.4230/LIPIcs.FSTTCS.2022.29}, volume = {250}, year = {2022}, } @article{12107, abstract = {The sensitivity of coarse-grained daily extreme precipitation to sea surface temperature is analyzed using satellite precipitation estimates over the 300–302.5 K range. A theoretical scaling is proposed, linking changes in coarse-grained precipitation to changes in fine-scale hourly precipitation area fraction and changes in conditional fine-scale precipitation rates. The analysis reveals that the extreme coarse-grained precipitation scaling with temperature (∼7%/K) is dominated by the fine-scale precipitating fraction scaling (∼6.5%/K) when using a 3 mm/h fine-scale threshold to delineate the precipitating fraction. These results are shown to be robust to the selection of the precipitation product and to the percentile used to characterize the extreme. This new coarse-grained scaling is further related to the well-known scaling for fine-scale precipitation extremes, and suggests a compensation between thermodynamic and dynamic contributions or that both contributions are small with respect to that of fractional coverage. These results suggest that processes responsible for the changes in fractional coverage are to be accounted for to assess the sensitivity of coarse-grained extreme daily precipitation to surface temperature.}, author = {Roca, Rémy and De Meyer, Victorien and Muller, Caroline J}, issn = {1944-8007}, journal = {Geophysical Research Letters}, number = {24}, publisher = {Wiley}, title = {{Precipitating fraction, not intensity, explains extreme coarse-grained precipitation Clausius-Clapeyron scaling with sea surface temperature over tropical oceans}}, doi = {10.1029/2022GL100624}, volume = {49}, year = {2022}, } @article{12108, abstract = {The sequential exchange of filament composition to increase filament curvature was proposed as a mechanism for how some biological polymers deform and cut membranes. The relationship between the filament composition and its mechanical effect is lacking. We develop a kinetic model for the assembly of composite filaments that includes protein–membrane adhesion, filament mechanics and membrane mechanics. We identify the physical conditions for such a membrane remodeling and show this mechanism of sequential polymer assembly lowers the energetic barrier for membrane deformation.}, author = {Meadowcroft, Billie and Palaia, Ivan and Pfitzner, Anna Katharina and Roux, Aurélien and Baum, Buzz and Šarić, Anđela}, issn = {1079-7114}, journal = {Physical Review Letters}, number = {26}, publisher = {American Physical Society}, title = {{Mechanochemical rules for shape-shifting filaments that remodel membranes}}, doi = {10.1103/PhysRevLett.129.268101}, volume = {129}, year = {2022}, } @article{12109, abstract = {Kelvin probe force microscopy (KPFM) is a powerful tool for studying contact electrification (CE) at the nanoscale, but converting KPFM voltage maps to charge density maps is nontrivial due to long-range forces and complex system geometry. Here we present a strategy using finite-element method (FEM) simulations to determine the Green's function of the KPFM probe/insulator/ground system, which allows us to quantitatively extract surface charge. Testing our approach with synthetic data, we find that accounting for the atomic force microscope (AFM) tip, cone, and cantilever is necessary to recover a known input and that existing methods lead to gross miscalculation or even the incorrect sign of the underlying charge. Applying it to experimental data, we demonstrate its capacity to extract realistic surface charge densities and fine details from contact-charged surfaces. Our method gives a straightforward recipe to convert qualitative KPFM voltage data into quantitative charge data over a range of experimental conditions, enabling quantitative CE at the nanoscale.}, author = {Pertl, Felix and Sobarzo Ponce, Juan Carlos A and Shafeek, Lubuna B and Cramer, Tobias and Waitukaitis, Scott R}, issn = {2475-9953}, journal = {Physical Review Materials}, number = {12}, publisher = {American Physical Society}, title = {{Quantifying nanoscale charge density features of contact-charged surfaces with an FEM/KPFM-hybrid approach}}, doi = {10.1103/PhysRevMaterials.6.125605}, volume = {6}, year = {2022}, } @article{12110, abstract = {A recently proposed approach for avoiding the ultraviolet divergence of Hamiltonians with particle creation is based on interior-boundary conditions (IBCs). The approach works well in the non-relativistic case, i.e., for the Laplacian operator. Here, we study how the approach can be applied to Dirac operators. While this has successfully been done already in one space dimension, and more generally for codimension-1 boundaries, the situation of point sources in three dimensions corresponds to a codimension-3 boundary. One would expect that, for such a boundary, Dirac operators do not allow for boundary conditions because they are known not to allow for point interactions in 3D, which also correspond to a boundary condition. Indeed, we confirm this expectation here by proving that there is no self-adjoint operator on a (truncated) Fock space that would correspond to a Dirac operator with an IBC at configurations with a particle at the origin. However, we also present a positive result showing that there are self-adjoint operators with an IBC (on the boundary consisting of configurations with a particle at the origin) that are away from those configurations, given by a Dirac operator plus a sufficiently strong Coulomb potential.}, author = {Henheik, Sven Joscha and Tumulka, Roderich}, issn = {0022-2488}, journal = {Journal of Mathematical Physics}, number = {12}, publisher = {AIP Publishing}, title = {{Interior-boundary conditions for the Dirac equation at point sources in three dimensions}}, doi = {10.1063/5.0104675}, volume = {63}, year = {2022}, }