TY - JOUR AB - A light-triggered fabrication method extends the functionality of printable nanomaterials AU - Balazs, Daniel AU - Ibáñez, Maria ID - 14404 IS - 6665 JF - Science TI - Widening the use of 3D printing VL - 381 ER - TY - CONF AB - Entropic risk (ERisk) is an established risk measure in finance, quantifying risk by an exponential re-weighting of rewards. We study ERisk for the first time in the context of turn-based stochastic games with the total reward objective. This gives rise to an objective function that demands the control of systems in a risk-averse manner. We show that the resulting games are determined and, in particular, admit optimal memoryless deterministic strategies. This contrasts risk measures that previously have been considered in the special case of Markov decision processes and that require randomization and/or memory. We provide several results on the decidability and the computational complexity of the threshold problem, i.e. whether the optimal value of ERisk exceeds a given threshold. In the most general case, the problem is decidable subject to Shanuel’s conjecture. If all inputs are rational, the resulting threshold problem can be solved using algebraic numbers, leading to decidability via a polynomial-time reduction to the existential theory of the reals. Further restrictions on the encoding of the input allow the solution of the threshold problem in NP∩coNP. Finally, an approximation algorithm for the optimal value of ERisk is provided. AU - Baier, Christel AU - Chatterjee, Krishnendu AU - Meggendorfer, Tobias AU - Piribauer, Jakob ID - 14417 SN - 9783959772921 T2 - 48th International Symposium on Mathematical Foundations of Computer Science TI - Entropic risk for turn-based stochastic games VL - 272 ER - TY - JOUR AB - Isomanifolds are the generalization of isosurfaces to arbitrary dimension and codimension, i.e., submanifolds of Rd defined as the zero set of some multivariate multivalued smooth function f:Rd→Rd−n, where n is the intrinsic dimension of the manifold. A natural way to approximate a smooth isomanifold M=f−1(0) is to consider its piecewise linear (PL) approximation M^ based on a triangulation T of the ambient space Rd. In this paper, we describe a simple algorithm to trace isomanifolds from a given starting point. The algorithm works for arbitrary dimensions n and d, and any precision D. Our main result is that, when f (or M) has bounded complexity, the complexity of the algorithm is polynomial in d and δ=1/D (and unavoidably exponential in n). Since it is known that for δ=Ω(d2.5), M^ is O(D2)-close and isotopic to M , our algorithm produces a faithful PL-approximation of isomanifolds of bounded complexity in time polynomial in d. Combining this algorithm with dimensionality reduction techniques, the dependency on d in the size of M^ can be completely removed with high probability. We also show that the algorithm can handle isomanifolds with boundary and, more generally, isostratifolds. The algorithm for isomanifolds with boundary has been implemented and experimental results are reported, showing that it is practical and can handle cases that are far ahead of the state-of-the-art. AU - Boissonnat, Jean Daniel AU - Kachanovich, Siargey AU - Wintraecken, Mathijs ID - 12960 IS - 2 JF - SIAM Journal on Computing SN - 0097-5397 TI - Tracing isomanifolds in Rd in time polynomial in d using Coxeter–Freudenthal–Kuhn triangulations VL - 52 ER - TY - JOUR AB - We propose a characterization of discrete analytical spheres, planes and lines in the body-centered cubic (BCC) grid, both in the Cartesian and in the recently proposed alternative compact coordinate system, in which each integer triplet addresses some voxel in the grid. We define spheres and planes through double Diophantine inequalities and investigate their relevant topological features, such as functionality or the interrelation between the thickness of the objects and their connectivity and separation properties. We define lines as the intersection of planes. The number of the planes (up to six) is equal to the number of the pairs of faces of a BCC voxel that are parallel to the line. AU - Čomić, Lidija AU - Largeteau-Skapin, Gaëlle AU - Zrour, Rita AU - Biswas, Ranita AU - Andres, Eric ID - 13134 IS - 10 JF - Pattern Recognition SN - 0031-3203 TI - Discrete analytical objects in the body-centered cubic grid VL - 142 ER - TY - JOUR AB - Physical catalysts often have multiple sites where reactions can take place. One prominent example is single-atom alloys, where the reactive dopant atoms can preferentially locate in the bulk or at different sites on the surface of the nanoparticle. However, ab initio modeling of catalysts usually only considers one site of the catalyst, neglecting the effects of multiple sites. Here, nanoparticles of copper doped with single-atom rhodium or palladium are modeled for the dehydrogenation of propane. Single-atom alloy nanoparticles are simulated at 400–600 K, using machine learning potentials trained on density functional theory calculations, and then the occupation of different single-atom active sites is identified using a similarity kernel. Further, the turnover frequency for all possible sites is calculated for propane dehydrogenation to propene through microkinetic modeling using density functional theory calculations. The total turnover frequencies of the whole nanoparticle are then described from both the population and the individual turnover frequency of each site. Under operating conditions, rhodium as a dopant is found to almost exclusively occupy (111) surface sites while palladium as a dopant occupies a greater variety of facets. Undercoordinated dopant surface sites are found to tend to be more reactive for propane dehydrogenation compared to the (111) surface. It is found that considering the dynamics of the single-atom alloy nanoparticle has a profound effect on the calculated catalytic activity of single-atom alloys by several orders of magnitude. AU - Bunting, Rhys AU - Wodaczek, Felix AU - Torabi, Tina AU - Cheng, Bingqing ID - 13216 IS - 27 JF - Journal of the American Chemical Society KW - Colloid and Surface Chemistry KW - Biochemistry KW - General Chemistry KW - Catalysis SN - 0002-7863 TI - Reactivity of single-atom alloy nanoparticles: Modeling the dehydrogenation of propane VL - 145 ER - TY - JOUR AB - To meet the physiological demands of the body, organs need to establish a functional tissue architecture and adequate size as the embryo develops to adulthood. In the liver, uni- and bipotent progenitor differentiation into hepatocytes and biliary epithelial cells (BECs), and their relative proportions, comprise the functional architecture. Yet, the contribution of individual liver progenitors at the organ level to both fates, and their specific proportion, is unresolved. Combining mathematical modelling with organ-wide, multispectral FRaeppli-NLS lineage tracing in zebrafish, we demonstrate that a precise BEC-to-hepatocyte ratio is established (i) fast, (ii) solely by heterogeneous lineage decisions from uni- and bipotent progenitors, and (iii) independent of subsequent cell type–specific proliferation. Extending lineage tracing to adulthood determined that embryonic cells undergo spatially heterogeneous three-dimensional growth associated with distinct environments. Strikingly, giant clusters comprising almost half a ventral lobe suggest lobe-specific dominant-like growth behaviours. We show substantial hepatocyte polyploidy in juveniles representing another hallmark of postembryonic liver growth. Our findings uncover heterogeneous progenitor contributions to tissue architecture-defining cell type proportions and postembryonic organ growth as key mechanisms forming the adult liver. AU - Unterweger, Iris A. AU - Klepstad, Julie AU - Hannezo, Edouard B AU - Lundegaard, Pia R. AU - Trusina, Ala AU - Ober, Elke A. ID - 14426 IS - 10 JF - PLoS Biology TI - Lineage tracing identifies heterogeneous hepatoblast contribution to cell lineages and postembryonic organ growth dynamics VL - 21 ER - TY - CONF AB - Suppose we have two hash functions h1 and h2, but we trust the security of only one of them. To mitigate this worry, we wish to build a hash combiner Ch1,h2 which is secure so long as one of the underlying hash functions is. This question has been well-studied in the regime of collision resistance. In this case, concatenating the two hash function outputs clearly works. Unfortunately, a long series of works (Boneh and Boyen, CRYPTO’06; Pietrzak, Eurocrypt’07; Pietrzak, CRYPTO’08) showed no (noticeably) shorter combiner for collision resistance is possible. In this work, we revisit this pessimistic state of affairs, motivated by the observation that collision-resistance is insufficient for many interesting applications of cryptographic hash functions anyway. We argue the right formulation of the “hash combiner” is to build what we call random oracle (RO) combiners, utilizing stronger assumptions for stronger constructions. Indeed, we circumvent the previous lower bounds for collision resistance by constructing a simple length-preserving RO combiner C˜h1,h2Z1,Z2(M)=h1(M,Z1)⊕h2(M,Z2),where Z1,Z2 are random salts of appropriate length. We show that this extra randomness is necessary for RO combiners, and indeed our construction is somewhat tight with this lower bound. On the negative side, we show that one cannot generically apply the composition theorem to further replace “monolithic” hash functions h1 and h2 by some simpler indifferentiable construction (such as the Merkle-Damgård transformation) from smaller components, such as fixed-length compression functions. Finally, despite this issue, we directly prove collision resistance of the Merkle-Damgård variant of our combiner, where h1 and h2 are replaced by iterative Merkle-Damgård hashes applied to a fixed-length compression function. Thus, we can still subvert the concatenation barrier for collision-resistance combiners while utilizing practically small fixed-length components underneath. AU - Dodis, Yevgeniy AU - Ferguson, Niels AU - Goldin, Eli AU - Hall, Peter AU - Pietrzak, Krzysztof Z ID - 14428 SN - 0302-9743 T2 - 43rd Annual International Cryptology Conference TI - Random oracle combiners: Breaking the concatenation barrier for collision-resistance VL - 14082 ER - TY - CHAP AB - Imaging of the immunological synapse (IS) between dendritic cells (DCs) and T cells in suspension is hampered by suboptimal alignment of cell-cell contacts along the vertical imaging plane. This requires optical sectioning that often results in unsatisfactory resolution in time and space. Here, we present a workflow where DCs and T cells are confined between a layer of glass and polydimethylsiloxane (PDMS) that orients the cells along one, horizontal imaging plane, allowing for fast en-face-imaging of the DC-T cell IS. AU - Leithner, Alexander F AU - Merrin, Jack AU - Sixt, Michael K ED - Baldari, Cosima ED - Dustin, Michael ID - 13052 SN - 1064-3745 T2 - The Immune Synapse TI - En-Face Imaging of T Cell-Dendritic Cell Immunological Synapses VL - 2654 ER - TY - JOUR AB - Let X be a sufficiently large positive integer. We prove that one may choose a subset S of primes with cardinality O(logX) such that a positive proportion of integers less than X can be represented by x2+py2 for at least one p∈S. AU - Diao, Yijie ID - 12406 JF - Acta Arithmetica KW - Algebra KW - Number Theory SN - 0065-1036 TI - Density of the union of positive diagonal binary quadratic forms VL - 207 ER - TY - JOUR AB - Recent quantum technologies have established precise quantum control of various microscopic systems using electromagnetic waves. Interfaces based on cryogenic cavity electro-optic systems are particularly promising, due to the direct interaction between microwave and optical fields in the quantum regime. Quantum optical control of superconducting microwave circuits has been precluded so far due to the weak electro-optical coupling as well as quasi-particles induced by the pump laser. Here we report the coherent control of a superconducting microwave cavity using laser pulses in a multimode electro-optical device at millikelvin temperature with near-unity cooperativity. Both the stationary and instantaneous responses of the microwave and optical modes comply with the coherent electro-optical interaction, and reveal only minuscule amount of excess back-action with an unanticipated time delay. Our demonstration enables wide ranges of applications beyond quantum transductions, from squeezing and quantum non-demolition measurements of microwave fields, to entanglement generation and hybrid quantum networks. AU - Qiu, Liu AU - Sahu, Rishabh AU - Hease, William J AU - Arnold, Georg M AU - Fink, Johannes M ID - 13200 JF - Nature Communications TI - Coherent optical control of a superconducting microwave cavity via electro-optical dynamical back-action VL - 14 ER - TY - JOUR AB - How do statistical dependencies in measurement noise influence high-dimensional inference? To answer this, we study the paradigmatic spiked matrix model of principal components analysis (PCA), where a rank-one matrix is corrupted by additive noise. We go beyond the usual independence assumption on the noise entries, by drawing the noise from a low-order polynomial orthogonal matrix ensemble. The resulting noise correlations make the setting relevant for applications but analytically challenging. We provide characterization of the Bayes optimal limits of inference in this model. If the spike is rotation invariant, we show that standard spectral PCA is optimal. However, for more general priors, both PCA and the existing approximate message-passing algorithm (AMP) fall short of achieving the information-theoretic limits, which we compute using the replica method from statistical physics. We thus propose an AMP, inspired by the theory of adaptive Thouless–Anderson–Palmer equations, which is empirically observed to saturate the conjectured theoretical limit. This AMP comes with a rigorous state evolution analysis tracking its performance. Although we focus on specific noise distributions, our methodology can be generalized to a wide class of trace matrix ensembles at the cost of more involved expressions. Finally, despite the seemingly strong assumption of rotation-invariant noise, our theory empirically predicts algorithmic performance on real data, pointing at strong universality properties. AU - Barbier, Jean AU - Camilli, Francesco AU - Mondelli, Marco AU - Sáenz, Manuel ID - 13315 IS - 30 JF - Proceedings of the National Academy of Sciences of the United States of America TI - Fundamental limits in structured principal component analysis and how to reach them VL - 120 ER - TY - JOUR AB - Traditionally, nuclear spin is not considered to affect biological processes. Recently, this has changed as isotopic fractionation that deviates from classical mass dependence was reported both in vitro and in vivo. In these cases, the isotopic effect correlates with the nuclear magnetic spin. Here, we show nuclear spin effects using stable oxygen isotopes (16O, 17O, and 18O) in two separate setups: an artificial dioxygen production system and biological aquaporin channels in cells. We observe that oxygen dynamics in chiral environments (in particular its transport) depend on nuclear spin, suggesting future applications for controlled isotope separation to be used, for instance, in NMR. To demonstrate the mechanism behind our findings, we formulate theoretical models based on a nuclear-spin-enhanced switch between electronic spin states. Accounting for the role of nuclear spin in biology can provide insights into the role of quantum effects in living systems and help inspire the development of future biotechnology solutions. AU - Vardi, Ofek AU - Maroudas-Sklare, Naama AU - Kolodny, Yuval AU - Volosniev, Artem AU - Saragovi, Amijai AU - Galili, Nir AU - Ferrera, Stav AU - Ghazaryan, Areg AU - Yuran, Nir AU - Affek, Hagit P. AU - Luz, Boaz AU - Goldsmith, Yonaton AU - Keren, Nir AU - Yochelis, Shira AU - Halevy, Itay AU - Lemeshko, Mikhail AU - Paltiel, Yossi ID - 14037 IS - 32 JF - Proceedings of the National Academy of Sciences of the United States of America TI - Nuclear spin effects in biological processes VL - 120 ER - TY - JOUR AB - We study the eigenvalue trajectories of a time dependent matrix Gt=H+itvv∗ for t≥0, where H is an N×N Hermitian random matrix and v is a unit vector. In particular, we establish that with high probability, an outlier can be distinguished at all times t>1+N−1/3+ϵ, for any ϵ>0. The study of this natural process combines elements of Hermitian and non-Hermitian analysis, and illustrates some aspects of the intrinsic instability of (even weakly) non-Hermitian matrices. AU - Dubach, Guillaume AU - Erdös, László ID - 12683 JF - Electronic Communications in Probability TI - Dynamics of a rank-one perturbation of a Hermitian matrix VL - 28 ER - TY - JOUR AB - We consider the fluctuations of regular functions f of a Wigner matrix W viewed as an entire matrix f (W). Going beyond the well-studied tracial mode, Trf (W), which is equivalent to the customary linear statistics of eigenvalues, we show that Trf (W)A is asymptotically normal for any nontrivial bounded deterministic matrix A. We identify three different and asymptotically independent modes of this fluctuation, corresponding to the tracial part, the traceless diagonal part and the off-diagonal part of f (W) in the entire mesoscopic regime, where we find that the off-diagonal modes fluctuate on a much smaller scale than the tracial mode. As a main motivation to study CLT in such generality on small mesoscopic scales, we determine the fluctuations in the eigenstate thermalization hypothesis (Phys. Rev. A 43 (1991) 2046–2049), that is, prove that the eigenfunction overlaps with any deterministic matrix are asymptotically Gaussian after a small spectral averaging. Finally, in the macroscopic regime our result also generalizes (Zh. Mat. Fiz. Anal. Geom. 9 (2013) 536–581, 611, 615) to complex W and to all crossover ensembles in between. The main technical inputs are the recent multiresolvent local laws with traceless deterministic matrices from the companion paper (Comm. Math. Phys. 388 (2021) 1005–1048). AU - Cipolloni, Giorgio AU - Erdös, László AU - Schröder, Dominik J ID - 12761 IS - 1 JF - Annals of Applied Probability SN - 1050-5164 TI - Functional central limit theorems for Wigner matrices VL - 33 ER - TY - JOUR AB - It is known that the Brauer--Manin obstruction to the Hasse principle is vacuous for smooth Fano hypersurfaces of dimension at least 3 over any number field. Moreover, for such varieties it follows from a general conjecture of Colliot-Thélène that the Brauer--Manin obstruction to the Hasse principle should be the only one, so that the Hasse principle is expected to hold. Working over the field of rational numbers and ordering Fano hypersurfaces of fixed degree and dimension by height, we prove that almost every such hypersurface satisfies the Hasse principle provided that the dimension is at least 3. This proves a conjecture of Poonen and Voloch in every case except for cubic surfaces. AU - Browning, Timothy D AU - Boudec, Pierre Le AU - Sawin, Will ID - 8682 IS - 3 JF - Annals of Mathematics SN - 0003-486X TI - The Hasse principle for random Fano hypersurfaces VL - 197 ER - TY - JOUR AB - Allometric settings of population dynamics models are appealing due to their parsimonious nature and broad utility when studying system level effects. Here, we parameterise the size-scaled Rosenzweig-MacArthur differential equations to eliminate prey-mass dependency, facilitating an in depth analytic study of the equations which incorporates scaling parameters’ contributions to coexistence. We define the functional response term to match empirical findings, and examine situations where metabolic theory derivations and observation diverge. The dynamical properties of the Rosenzweig-MacArthur system, encompassing the distribution of size-abundance equilibria, the scaling of period and amplitude of population cycling, and relationships between predator and prey abundances, are consistent with empirical observation. Our parameterisation is an accurate minimal model across 15+ orders of mass magnitude. AU - Mckerral, Jody C. AU - Kleshnina, Maria AU - Ejov, Vladimir AU - Bartle, Louise AU - Mitchell, James G. AU - Filar, Jerzy A. ID - 12706 IS - 2 JF - PLoS One TI - Empirical parameterisation and dynamical analysis of the allometric Rosenzweig-MacArthur equations VL - 18 ER - TY - JOUR AB - Phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) plays an essential role in neuronal activities through interaction with various proteins involved in signaling at membranes. However, the distribution pattern of PI(4,5)P2 and the association with these proteins on the neuronal cell membranes remain elusive. In this study, we established a method for visualizing PI(4,5)P2 by SDS-digested freeze-fracture replica labeling (SDS-FRL) to investigate the quantitative nanoscale distribution of PI(4,5)P2 in cryo-fixed brain. We demonstrate that PI(4,5)P2 forms tiny clusters with a mean size of ∼1000 nm2 rather than randomly distributed in cerebellar neuronal membranes in male C57BL/6J mice. These clusters show preferential accumulation in specific membrane compartments of different cell types, in particular, in Purkinje cell (PC) spines and granule cell (GC) presynaptic active zones. Furthermore, we revealed extensive association of PI(4,5)P2 with CaV2.1 and GIRK3 across different membrane compartments, whereas its association with mGluR1α was compartment specific. These results suggest that our SDS-FRL method provides valuable insights into the physiological functions of PI(4,5)P2 in neurons. AU - Eguchi, Kohgaku AU - Le Monnier, Elodie AU - Shigemoto, Ryuichi ID - 13202 IS - 23 JF - The Journal of Neuroscience SN - 0270-6474 TI - Nanoscale phosphoinositide distribution on cell membranes of mouse cerebellar neurons VL - 43 ER - TY - JOUR AB - We apply a variant of the square-sieve to produce an upper bound for the number of rational points of bounded height on a family of surfaces that admit a fibration over P1 whose general fibre is a hyperelliptic curve. The implied constant does not depend on the coefficients of the polynomial defining the surface. AU - Bonolis, Dante AU - Browning, Timothy D ID - 12916 IS - 1 JF - Annali della Scuola Normale Superiore di Pisa - Classe di Scienze SN - 0391-173X TI - Uniform bounds for rational points on hyperelliptic fibrations VL - 24 ER - TY - THES AB - Animals exhibit a remarkable ability to learn and remember new behaviors, skills, and associations throughout their lifetime. These capabilities are made possible thanks to a variety of changes in the brain throughout adulthood, regrouped under the term "plasticity". Some cells in the brain —neurons— and specifically changes in the connections between neurons, the synapses, were shown to be crucial for the formation, selection, and consolidation of memories from past experiences. These ongoing changes of synapses across time are called synaptic plasticity. Understanding how a myriad of biochemical processes operating at individual synapses can somehow work in concert to give rise to meaningful changes in behavior is a fascinating problem and an active area of research. However, the experimental search for the precise plasticity mechanisms at play in the brain is daunting, as it is difficult to control and observe synapses during learning. Theoretical approaches have thus been the default method to probe the plasticity-behavior connection. Such studies attempt to extract unifying principles across synapses and model all observed synaptic changes using plasticity rules: equations that govern the evolution of synaptic strengths across time in neuronal network models. These rules can use many relevant quantities to determine the magnitude of synaptic changes, such as the precise timings of pre- and postsynaptic action potentials, the recent neuronal activity levels, the state of neighboring synapses, etc. However, analytical studies rely heavily on human intuition and are forced to make simplifying assumptions about plasticity rules. In this thesis, we aim to assist and augment human intuition in this search for plasticity rules. We explore whether a numerical approach could automatically discover the plasticity rules that elicit desired behaviors in large networks of interconnected neurons. This approach is dubbed meta-learning synaptic plasticity: learning plasticity rules which themselves will make neuronal networks learn how to solve a desired task. We first write all the potential plasticity mechanisms to consider using a single expression with adjustable parameters. We then optimize these plasticity parameters using evolutionary strategies or Bayesian inference on tasks known to involve synaptic plasticity, such as familiarity detection and network stabilization. We show that these automated approaches are powerful tools, able to complement established analytical methods. By comprehensively screening plasticity rules at all synapse types in realistic, spiking neuronal network models, we discover entire sets of degenerate plausible plasticity rules that reliably elicit memory-related behaviors. Our approaches allow for more robust experimental predictions, by abstracting out the idiosyncrasies of individual plasticity rules, and provide fresh insights on synaptic plasticity in spiking network models. AU - Confavreux, Basile J ID - 14422 SN - 2663 - 337X TI - Synapseek: Meta-learning synaptic plasticity rules ER - TY - THES AB - Superconductivity has many important applications ranging from levitating trains over qubits to MRI scanners. The phenomenon is successfully modeled by Bardeen-Cooper-Schrieffer (BCS) theory. From a mathematical perspective, BCS theory has been studied extensively for systems without boundary. However, little is known in the presence of boundaries. With the help of numerical methods physicists observed that the critical temperature may increase in the presence of a boundary. The goal of this thesis is to understand the influence of boundaries on the critical temperature in BCS theory and to give a first rigorous justification of these observations. On the way, we also study two-body Schrödinger operators on domains with boundaries and prove additional results for superconductors without boundary. BCS theory is based on a non-linear functional, where the minimizer indicates whether the system is superconducting or in the normal, non-superconducting state. By considering the Hessian of the BCS functional at the normal state, one can analyze whether the normal state is possibly a minimum of the BCS functional and estimate the critical temperature. The Hessian turns out to be a linear operator resembling a Schrödinger operator for two interacting particles, but with more complicated kinetic energy. As a first step, we study the two-body Schrödinger operator in the presence of boundaries. For Neumann boundary conditions, we prove that the addition of a boundary can create new eigenvalues, which correspond to the two particles forming a bound state close to the boundary. Second, we need to understand superconductivity in the translation invariant setting. While in three dimensions this has been extensively studied, there is no mathematical literature for the one and two dimensional cases. In dimensions one and two, we compute the weak coupling asymptotics of the critical temperature and the energy gap in the translation invariant setting. We also prove that their ratio is independent of the microscopic details of the model in the weak coupling limit; this property is referred to as universality. In the third part, we study the critical temperature of superconductors in the presence of boundaries. We start by considering the one-dimensional case of a half-line with contact interaction. Then, we generalize the results to generic interactions and half-spaces in one, two and three dimensions. Finally, we compare the critical temperature of a quarter space in two dimensions to the critical temperatures of a half-space and of the full space. AU - Roos, Barbara ID - 14374 SN - 2663 - 337X TI - Boundary superconductivity in BCS theory ER - TY - JOUR AB - We consider the linear BCS equation, determining the BCS critical temperature, in the presence of a boundary, where Dirichlet boundary conditions are imposed. In the one-dimensional case with point interactions, we prove that the critical temperature is strictly larger than the bulk value, at least at weak coupling. In particular, the Cooper-pair wave function localizes near the boundary, an effect that cannot be modeled by effective Neumann boundary conditions on the order parameter as often imposed in Ginzburg–Landau theory. We also show that the relative shift in critical temperature vanishes if the coupling constant either goes to zero or to infinity. AU - Hainzl, Christian AU - Roos, Barbara AU - Seiringer, Robert ID - 13207 IS - 4 JF - Journal of Spectral Theory SN - 1664-039X TI - Boundary superconductivity in the BCS model VL - 12 ER - TY - JOUR AB - The classical infinitesimal model is a simple and robust model for the inheritance of quantitative traits. In this model, a quantitative trait is expressed as the sum of a genetic and an environmental component, and the genetic component of offspring traits within a family follows a normal distribution around the average of the parents’ trait values, and has a variance that is independent of the parental traits. In previous work, we showed that when trait values are determined by the sum of a large number of additive Mendelian factors, each of small effect, one can justify the infinitesimal model as a limit of Mendelian inheritance. In this paper, we show that this result extends to include dominance. We define the model in terms of classical quantities of quantitative genetics, before justifying it as a limit of Mendelian inheritance as the number, M, of underlying loci tends to infinity. As in the additive case, the multivariate normal distribution of trait values across the pedigree can be expressed in terms of variance components in an ancestral population and probabilities of identity by descent determined by the pedigree. Now, with just first-order dominance effects, we require two-, three-, and four-way identities. We also show that, even if we condition on parental trait values, the “shared” and “residual” components of trait values within each family will be asymptotically normally distributed as the number of loci tends to infinity, with an error of order 1/M−−√⁠. We illustrate our results with some numerical examples. AU - Barton, Nicholas H AU - Etheridge, Alison M. AU - Véber, Amandine ID - 14452 IS - 2 JF - Genetics SN - 0016-6731 TI - The infinitesimal model with dominance VL - 225 ER - TY - DATA AB - The classical infinitesimal model is a simple and robust model for the inheritance of quantitative traits. In this model, a quantitative trait is expressed as the sum of a genetic and a non-genetic (environmental) component and the genetic component of offspring traits within a family follows a normal distribution around the average of the parents’ trait values, and has a variance that is independent of the trait values of the parents. Although the trait distribution across the whole population can be far from normal, the trait distributions within families are normally distributed with a variance-covariance matrix that is determined entirely by that in the ancestral population and the probabilities of identity determined by the pedigree. Moreover, conditioning on some of the trait values within the pedigree has predictable effects on the mean and variance within and between families. In previous work, Barton et al. (2017), we showed that when trait values are determined by the sum of a large number of Mendelian factors, each of small effect, one can justify the infinitesimal model as limit of Mendelian inheritance. It was also shown that under some forms of epistasis, trait values within a family are still normally distributed. AU - Barton, Nicholas H ID - 12949 KW - Quantitative genetics KW - infinitesimal model TI - The infinitesimal model with dominance ER - TY - CONF AB - Communication-reduction techniques are a popular way to improve scalability in data-parallel training of deep neural networks (DNNs). The recent emergence of large language models such as GPT has created the need for new approaches to exploit data-parallelism. Among these, fully-sharded data parallel (FSDP) training is highly popular, yet it still encounters scalability bottlenecks. One reason is that applying compression techniques to FSDP is challenging: as the vast majority of the communication involves the model’s weights, direct compression alters convergence and leads to accuracy loss. We present QSDP, a variant of FSDP which supports both gradient and weight quantization with theoretical guarantees, is simple to implement and has essentially no overheads. To derive QSDP we prove that a natural modification of SGD achieves convergence even when we only maintain quantized weights, and thus the domain over which we train consists of quantized points and is, therefore, highly non-convex. We validate this approach by training GPT-family models with up to 1.3 billion parameters on a multi-node cluster. Experiments show that QSDP preserves model accuracy, while completely removing the communication bottlenecks of FSDP, providing end-to-end speedups of up to 2.2x. AU - Markov, Ilia AU - Vladu, Adrian AU - Guo, Qi AU - Alistarh, Dan-Adrian ID - 14461 T2 - Proceedings of the 40th International Conference on Machine Learning TI - Quantized distributed training of large models with convergence guarantees VL - 202 ER - TY - CONF AB - We study fine-grained error bounds for differentially private algorithms for counting under continual observation. Our main insight is that the matrix mechanism when using lower-triangular matrices can be used in the continual observation model. More specifically, we give an explicit factorization for the counting matrix Mcount and upper bound the error explicitly. We also give a fine-grained analysis, specifying the exact constant in the upper bound. Our analysis is based on upper and lower bounds of the completely bounded norm (cb-norm) of Mcount . Along the way, we improve the best-known bound of 28 years by Mathias (SIAM Journal on Matrix Analysis and Applications, 1993) on the cb-norm of Mcount for a large range of the dimension of Mcount. Furthermore, we are the first to give concrete error bounds for various problems under continual observation such as binary counting, maintaining a histogram, releasing an approximately cut-preserving synthetic graph, many graph-based statistics, and substring and episode counting. Finally, we note that our result can be used to get a fine-grained error bound for non-interactive local learning and the first lower bounds on the additive error for (ϵ,δ)-differentially-private counting under continual observation. Subsequent to this work, Henzinger et al. (SODA, 2023) showed that our factorization also achieves fine-grained mean-squared error. AU - Fichtenberger, Hendrik AU - Henzinger, Monika H AU - Upadhyay, Jalaj ID - 14462 T2 - Proceedings of the 40th International Conference on Machine Learning TI - Constant matters: Fine-grained error bound on differentially private continual observation VL - 202 ER - TY - CONF AB - Autoencoders are a popular model in many branches of machine learning and lossy data compression. However, their fundamental limits, the performance of gradient methods and the features learnt during optimization remain poorly understood, even in the two-layer setting. In fact, earlier work has considered either linear autoencoders or specific training regimes (leading to vanishing or diverging compression rates). Our paper addresses this gap by focusing on non-linear two-layer autoencoders trained in the challenging proportional regime in which the input dimension scales linearly with the size of the representation. Our results characterize the minimizers of the population risk, and show that such minimizers are achieved by gradient methods; their structure is also unveiled, thus leading to a concise description of the features obtained via training. For the special case of a sign activation function, our analysis establishes the fundamental limits for the lossy compression of Gaussian sources via (shallow) autoencoders. Finally, while the results are proved for Gaussian data, numerical simulations on standard datasets display the universality of the theoretical predictions. AU - Shevchenko, Aleksandr AU - Kögler, Kevin AU - Hassani, Hamed AU - Mondelli, Marco ID - 14459 T2 - Proceedings of the 40th International Conference on Machine Learning TI - Fundamental limits of two-layer autoencoders, and achieving them with gradient methods VL - 202 ER - TY - CONF AB - We provide an efficient implementation of the backpropagation algorithm, specialized to the case where the weights of the neural network being trained are sparse. Our algorithm is general, as it applies to arbitrary (unstructured) sparsity and common layer types (e.g., convolutional or linear). We provide a fast vectorized implementation on commodity CPUs, and show that it can yield speedups in end-to-end runtime experiments, both in transfer learning using already-sparsified networks, and in training sparse networks from scratch. Thus, our results provide the first support for sparse training on commodity hardware. AU - Nikdan, Mahdi AU - Pegolotti, Tommaso AU - Iofinova, Eugenia B AU - Kurtic, Eldar AU - Alistarh, Dan-Adrian ID - 14460 T2 - Proceedings of the 40th International Conference on Machine Learning TI - SparseProp: Efficient sparse backpropagation for faster training of neural networks at the edge VL - 202 ER - TY - CONF AB - Threshold secret sharing allows a dealer to split a secret s into n shares, such that any t shares allow for reconstructing s, but no t-1 shares reveal any information about s. Leakage-resilient secret sharing requires that the secret remains hidden, even when an adversary additionally obtains a limited amount of leakage from every share. Benhamouda et al. (CRYPTO’18) proved that Shamir’s secret sharing scheme is one bit leakage-resilient for reconstruction threshold t≥0.85n and conjectured that the same holds for t = c.n for any constant 0≤c≤1. Nielsen and Simkin (EUROCRYPT’20) showed that this is the best one can hope for by proving that Shamir’s scheme is not secure against one-bit leakage when t0c.n/log(n). In this work, we strengthen the lower bound of Nielsen and Simkin. We consider noisy leakage-resilience, where a random subset of leakages is replaced by uniformly random noise. We prove a lower bound for Shamir’s secret sharing, similar to that of Nielsen and Simkin, which holds even when a constant fraction of leakages is replaced by random noise. To this end, we first prove a lower bound on the share size of any noisy-leakage-resilient sharing scheme. We then use this lower bound to show that there exist universal constants c1, c2, such that for sufficiently large n it holds that Shamir’s secret sharing scheme is not noisy-leakage-resilient for t≤c1.n/log(n), even when a c2 fraction of leakages are replaced by random noise. AU - Hoffmann, Charlotte AU - Simkin, Mark ID - 14457 SN - 0302-9743 T2 - 8th International Conference on Cryptology and Information Security in Latin America TI - Stronger lower bounds for leakage-resilient secret sharing VL - 14168 ER - TY - CONF AB - We show for the first time that large-scale generative pretrained transformer (GPT) family models can be pruned to at least 50% sparsity in one-shot, without any retraining, at minimal loss of accuracy. This is achieved via a new pruning method called SparseGPT, specifically designed to work efficiently and accurately on massive GPT-family models. We can execute SparseGPT on the largest available open-source models, OPT-175B and BLOOM-176B, in under 4.5 hours, and can reach 60% unstructured sparsity with negligible increase in perplexity: remarkably, more than 100 billion weights from these models can be ignored at inference time. SparseGPT generalizes to semi-structured (2:4 and 4:8) patterns, and is compatible with weight quantization approaches. The code is available at: https://github.com/IST-DASLab/sparsegpt. AU - Frantar, Elias AU - Alistarh, Dan-Adrian ID - 14458 T2 - Proceedings of the 40th International Conference on Machine Learning TI - SparseGPT: Massive language models can be accurately pruned in one-shot VL - 202 ER - TY - JOUR AB - We investigate the potential of Multi-Objective, Deep Reinforcement Learning for stock and cryptocurrency single-asset trading: in particular, we consider a Multi-Objective algorithm which generalizes the reward functions and discount factor (i.e., these components are not specified a priori, but incorporated in the learning process). Firstly, using several important assets (BTCUSD, ETHUSDT, XRPUSDT, AAPL, SPY, NIFTY50), we verify the reward generalization property of the proposed Multi-Objective algorithm, and provide preliminary statistical evidence showing increased predictive stability over the corresponding Single-Objective strategy. Secondly, we show that the Multi-Objective algorithm has a clear edge over the corresponding Single-Objective strategy when the reward mechanism is sparse (i.e., when non-null feedback is infrequent over time). Finally, we discuss the generalization properties with respect to the discount factor. The entirety of our code is provided in open-source format. AU - Cornalba, Federico AU - Disselkamp, Constantin AU - Scassola, Davide AU - Helf, Christopher ID - 14451 JF - Neural Computing and Applications SN - 0941-0643 TI - Multi-objective reward generalization: improving performance of Deep Reinforcement Learning for applications in single-asset trading ER - TY - JOUR AB - In the presence of an obstacle, active particles condensate into a surface “wetting” layer due to persistent motion. If the obstacle is asymmetric, a rectification current arises in addition to wetting. Asymmetric geometries are therefore commonly used to concentrate microorganisms like bacteria and sperms. However, most studies neglect the fact that biological active matter is diverse, composed of individuals with distinct self-propulsions. Using simulations, we study a mixture of “fast” and “slow” active Brownian disks in two dimensions interacting with large half-disk obstacles. With this prototypical obstacle geometry, we analyze how the stationary collective behavior depends on the degree of self-propulsion “diversity,” defined as proportional to the difference between the self-propulsion speeds, while keeping the average self-propulsion speed fixed. A wetting layer rich in fast particles arises. The rectification current is amplified by speed diversity due to a superlinear dependence of rectification on self-propulsion speed, which arises from cooperative effects. Thus, the total rectification current cannot be obtained from an effective one-component active fluid with the same average self-propulsion speed, highlighting the importance of considering diversity in active matter. AU - Rojas Vega, Mauricio Nicolas AU - De Castro, Pablo AU - Soto, Rodrigo ID - 14442 IS - 10 JF - The European Physical Journal E SN - 1292-8941 TI - Mixtures of self-propelled particles interacting with asymmetric obstacles VL - 46 ER - TY - JOUR AB - We prove several results about substructures in Latin squares. First, we explain how to adapt our recent work on high-girth Steiner triple systems to the setting of Latin squares, resolving a conjecture of Linial that there exist Latin squares with arbitrarily high girth. As a consequence, we see that the number of order- n Latin squares with no intercalate (i.e., no 2×2 Latin subsquare) is at least (e−9/4n−o(n))n2. Equivalently, P[N=0]≥e−n2/4−o(n2)=e−(1+o(1))EN , where N is the number of intercalates in a uniformly random order- n Latin square. In fact, extending recent work of Kwan, Sah, and Sawhney, we resolve the general large-deviation problem for intercalates in random Latin squares, up to constant factors in the exponent: for any constant 0<δ≤1 we have P[N≤(1−δ)EN]=exp(−Θ(n2)) and for any constant δ>0 we have P[N≥(1+δ)EN]=exp(−Θ(n4/3logn)). Finally, as an application of some new general tools for studying substructures in random Latin squares, we show that in almost all order- n Latin squares, the number of cuboctahedra (i.e., the number of pairs of possibly degenerate 2×2 submatrices with the same arrangement of symbols) is of order n4, which is the minimum possible. As observed by Gowers and Long, this number can be interpreted as measuring ``how associative'' the quasigroup associated with the Latin square is. AU - Kwan, Matthew Alan AU - Sah, Ashwin AU - Sawhney, Mehtaab AU - Simkin, Michael ID - 14444 IS - 2 JF - Israel Journal of Mathematics SN - 0021-2172 TI - Substructures in Latin squares VL - 256 ER - TY - CONF AB - As AI and machine-learned software are used increasingly for making decisions that affect humans, it is imperative that they remain fair and unbiased in their decisions. To complement design-time bias mitigation measures, runtime verification techniques have been introduced recently to monitor the algorithmic fairness of deployed systems. Previous monitoring techniques assume full observability of the states of the (unknown) monitored system. Moreover, they can monitor only fairness properties that are specified as arithmetic expressions over the probabilities of different events. In this work, we extend fairness monitoring to systems modeled as partially observed Markov chains (POMC), and to specifications containing arithmetic expressions over the expected values of numerical functions on event sequences. The only assumptions we make are that the underlying POMC is aperiodic and starts in the stationary distribution, with a bound on its mixing time being known. These assumptions enable us to estimate a given property for the entire distribution of possible executions of the monitored POMC, by observing only a single execution. Our monitors observe a long run of the system and, after each new observation, output updated PAC-estimates of how fair or biased the system is. The monitors are computationally lightweight and, using a prototype implementation, we demonstrate their effectiveness on several real-world examples. AU - Henzinger, Thomas A AU - Kueffner, Konstantin AU - Mallik, Kaushik ID - 14454 SN - 0302-9743 T2 - 23rd International Conference on Runtime Verification TI - Monitoring algorithmic fairness under partial observations VL - 14245 ER - TY - JOUR AB - Recent work has paid close attention to the first principle of Granger causality, according to which cause precedes effect. In this context, the question may arise whether the detected direction of causality also reverses after the time reversal of unidirectionally coupled data. Recently, it has been shown that for unidirectionally causally connected autoregressive (AR) processes X → Y, after time reversal of data, the opposite causal direction Y → X is indeed detected, although typically as part of the bidirectional X↔ Y link. As we argue here, the answer is different when the measured data are not from AR processes but from linked deterministic systems. When the goal is the usual forward data analysis, cross-mapping-like approaches correctly detect X → Y, while Granger causality-like approaches, which should not be used for deterministic time series, detect causal independence X → Y. The results of backward causal analysis depend on the predictability of the reversed data. Unlike AR processes, observables from deterministic dynamical systems, even complex nonlinear ones, can be predicted well forward, while backward predictions can be difficult (notably when the time reversal of a function leads to one-to-many relations). To address this problem, we propose an approach based on models that provide multiple candidate predictions for the target, combined with a loss function that consideres only the best candidate. The resulting good forward and backward predictability supports the view that unidirectionally causally linked deterministic dynamical systems X → Y can be expected to detect the same link both before and after time reversal. AU - Jakubík, Jozef AU - Bui Thi Mai, Phuong AU - Chvosteková, Martina AU - Krakovská, Anna ID - 14446 IS - 4 JF - Measurement Science Review TI - Against the flow of time with multi-output models VL - 23 ER - TY - JOUR AB - Importance Climate change, pollution, urbanization, socioeconomic inequality, and psychosocial effects of the COVID-19 pandemic have caused massive changes in environmental conditions that affect brain health during the life span, both on a population level as well as on the level of the individual. How these environmental factors influence the brain, behavior, and mental illness is not well known. Observations A research strategy enabling population neuroscience to contribute to identify brain mechanisms underlying environment-related mental illness by leveraging innovative enrichment tools for data federation, geospatial observation, climate and pollution measures, digital health, and novel data integration techniques is described. This strategy can inform innovative treatments that target causal cognitive and molecular mechanisms of mental illness related to the environment. An example is presented of the environMENTAL Project that is leveraging federated cohort data of over 1.5 million European citizens and patients enriched with deep phenotyping data from large-scale behavioral neuroimaging cohorts to identify brain mechanisms related to environmental adversity underlying symptoms of depression, anxiety, stress, and substance misuse. Conclusions and Relevance This research will lead to the development of objective biomarkers and evidence-based interventions that will significantly improve outcomes of environment-related mental illness. AU - Schumann, Gunter AU - Andreassen, Ole A. AU - Banaschewski, Tobias AU - Calhoun, Vince D. AU - Clinton, Nicholas AU - Desrivieres, Sylvane AU - Brandlistuen, Ragnhild Eek AU - Feng, Jianfeng AU - Hese, Soeren AU - Hitchen, Esther AU - Hoffmann, Per AU - Jia, Tianye AU - Jirsa, Viktor AU - Marquand, Andre F. AU - Nees, Frauke AU - Nöthen, Markus M. AU - Novarino, Gaia AU - Polemiti, Elli AU - Ralser, Markus AU - Rapp, Michael AU - Schepanski, Kerstin AU - Schikowski, Tamara AU - Slater, Mel AU - Sommer, Peter AU - Stahl, Bernd Carsten AU - Thompson, Paul M. AU - Twardziok, Sven AU - Van Der Meer, Dennis AU - Walter, Henrik AU - Westlye, Lars ID - 14443 IS - 10 JF - JAMA Psychiatry TI - Addressing global environmental challenges to mental health using population neuroscience: A review VL - 80 ER - TY - JOUR AB - We study the Fröhlich polaron model in R3, and establish the subleading term in the strong coupling asymptotics of its ground state energy, corresponding to the quantum corrections to the classical energy determined by the Pekar approximation. AU - Brooks, Morris AU - Seiringer, Robert ID - 14441 JF - Communications in Mathematical Physics SN - 0010-3616 TI - The Fröhlich Polaron at strong coupling: Part I - The quantum correction to the classical energy VL - 404 ER - TY - CONF AB - We consider the problem of solving LP relaxations of MAP-MRF inference problems, and in particular the method proposed recently in [16], [35]. As a key computational subroutine, it uses a variant of the Frank-Wolfe (FW) method to minimize a smooth convex function over a combinatorial polytope. We propose an efficient implementation of this subroutine based on in-face Frank-Wolfe directions, introduced in [4] in a different context. More generally, we define an abstract data structure for a combinatorial subproblem that enables in-face FW directions, and describe its specialization for tree-structured MAP-MRF inference subproblems. Experimental results indicate that the resulting method is the current state-of-art LP solver for some classes of problems. Our code is available at pub.ist.ac.at/~vnk/papers/IN-FACE-FW.html. AU - Kolmogorov, Vladimir ID - 14448 SN - 1063-6919 T2 - Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition TI - Solving relaxations of MAP-MRF problems: Combinatorial in-face Frank-Wolfe directions VL - 2023 ER - TY - JOUR AB - Cytosine methylation within CG dinucleotides (mCG) can be epigenetically inherited over many generations. Such inheritance is thought to be mediated by a semiconservative mechanism that produces binary present/absent methylation patterns. However, we show here that in Arabidopsis thaliana h1ddm1 mutants, intermediate heterochromatic mCG is stably inherited across many generations and is quantitatively associated with transposon expression. We develop a mathematical model that estimates the rates of semiconservative maintenance failure and de novo methylation at each transposon, demonstrating that mCG can be stably inherited at any level via a dynamic balance of these activities. We find that DRM2 – the core methyltransferase of the RNA-directed DNA methylation pathway – catalyzes most of the heterochromatic de novo mCG, with de novo rates orders of magnitude higher than previously thought, whereas chromomethylases make smaller contributions. Our results demonstrate that stable epigenetic inheritance of mCG in plant heterochromatin is enabled by extensive de novo methylation. AU - Lyons, David B. AU - Briffa, Amy AU - He, Shengbo AU - Choi, Jaemyung AU - Hollwey, Elizabeth AU - Colicchio, Jack AU - Anderson, Ian AU - Feng, Xiaoqi AU - Howard, Martin AU - Zilberman, Daniel ID - 12672 IS - 3 JF - Cell Reports TI - Extensive de novo activity stabilizes epigenetic inheritance of CG methylation in Arabidopsis transposons VL - 42 ER - TY - JOUR AB - We consider the large polaron described by the Fröhlich Hamiltonian and study its energy-momentum relation defined as the lowest possible energy as a function of the total momentum. Using a suitable family of trial states, we derive an optimal parabolic upper bound for the energy-momentum relation in the limit of strong coupling. The upper bound consists of a momentum independent term that agrees with the predicted two-term expansion for the ground state energy of the strongly coupled polaron at rest and a term that is quadratic in the momentum with coefficient given by the inverse of twice the classical effective mass introduced by Landau and Pekar. AU - Mitrouskas, David Johannes AU - Mysliwy, Krzysztof AU - Seiringer, Robert ID - 13178 JF - Forum of Mathematics TI - Optimal parabolic upper bound for the energy-momentum relation of a strongly coupled polaron VL - 11 ER - TY - JOUR AB - Intercellular signaling molecules, known as morphogens, act at a long range in developing tissues to provide spatial information and control properties such as cell fate and tissue growth. The production, transport, and removal of morphogens shape their concentration profiles in time and space. Downstream signaling cascades and gene regulatory networks within cells then convert the spatiotemporal morphogen profiles into distinct cellular responses. Current challenges are to understand the diverse molecular and cellular mechanisms underlying morphogen gradient formation, as well as the logic of downstream regulatory circuits involved in morphogen interpretation. This knowledge, combining experimental and theoretical results, is essential to understand emerging properties of morphogen-controlled systems, such as robustness and scaling. AU - Kicheva, Anna AU - Briscoe, James ID - 14484 JF - Annual Review of Cell and Developmental Biology SN - 1081-0706 TI - Control of tissue development by morphogens VL - 39 ER - TY - JOUR AB - Portrait viewpoint and illumination editing is an important problem with several applications in VR/AR, movies, and photography. Comprehensive knowledge of geometry and illumination is critical for obtaining photorealistic results. Current methods are unable to explicitly model in 3D while handling both viewpoint and illumination editing from a single image. In this paper, we propose VoRF, a novel approach that can take even a single portrait image as input and relight human heads under novel illuminations that can be viewed from arbitrary viewpoints. VoRF represents a human head as a continuous volumetric field and learns a prior model of human heads using a coordinate-based MLP with individual latent spaces for identity and illumination. The prior model is learned in an auto-decoder manner over a diverse class of head shapes and appearances, allowing VoRF to generalize to novel test identities from a single input image. Additionally, VoRF has a reflectance MLP that uses the intermediate features of the prior model for rendering One-Light-at-A-Time (OLAT) images under novel views. We synthesize novel illuminations by combining these OLAT images with target environment maps. Qualitative and quantitative evaluations demonstrate the effectiveness of VoRF for relighting and novel view synthesis, even when applied to unseen subjects under uncontrolled illumination. This work is an extension of Rao et al. (VoRF: Volumetric Relightable Faces 2022). We provide extensive evaluation and ablative studies of our model and also provide an application, where any face can be relighted using textual input. AU - Rao, Pramod AU - Mallikarjun, B. R. AU - Fox, Gereon AU - Weyrich, Tim AU - Bickel, Bernd AU - Pfister, Hanspeter AU - Matusik, Wojciech AU - Zhan, Fangneng AU - Tewari, Ayush AU - Theobalt, Christian AU - Elgharib, Mohamed ID - 14488 JF - International Journal of Computer Vision SN - 0920-5691 TI - A deeper analysis of volumetric relightiable faces ER - TY - JOUR AB - High Mountain Asia (HMA) is among the most vulnerable water towers globally and yet future projections of water availability in and from its high-mountain catchments remain uncertain, as their hydrologic response to ongoing environmental changes is complex. Mechanistic modeling approaches incorporating cryospheric, hydrological, and vegetation processes in high spatial, temporal, and physical detail have never been applied for high-elevation catchments of HMA. We use a land surface model at high spatial and temporal resolution (100 m and hourly) to simulate the coupled dynamics of energy, water, and vegetation for the 350 km2 Langtang catchment (Nepal). We compare our model outputs for one hydrological year against a large set of observations to gain insight into the partitioning of the water balance at the subseasonal scale and across elevation bands. During the simulated hydrological year, we find that evapotranspiration is a key component of the total water balance, as it causes about the equivalent of 20% of all the available precipitation or 154% of the water production from glacier melt in the basin to return directly to the atmosphere. The depletion of the cryospheric water budget is dominated by snow melt, but at high elevations is primarily dictated by snow and ice sublimation. Snow sublimation is the dominant vapor flux (49%) at the catchment scale, accounting for the equivalent of 11% of snowfall, 17% of snowmelt, and 75% of ice melt, respectively. We conclude that simulations should consider sublimation and other evaporative fluxes explicitly, as otherwise water balance estimates can be ill-quantified. AU - Buri, Pascal AU - Fatichi, Simone AU - Shaw, Thomas AU - Miles, Evan S. AU - Mccarthy, Michael AU - Fyffe, Catriona Louise AU - Fugger, Stefan AU - Ren, Shaoting AU - Kneib, Marin AU - Jouberton, Achille AU - Steiner, Jakob AU - Fujita, Koji AU - Pellicciotti, Francesca ID - 14487 IS - 10 JF - Water Resources Research SN - 0043-1397 TI - Land surface modeling in the Himalayas: On the importance of evaporative fluxes for the water balance of a high-elevation catchment VL - 59 ER - TY - CONF AB - Batching is a technique that stores multiple keys/values in each node of a data structure. In sequential search data structures, batching reduces latency by reducing the number of cache misses and shortening the chain of pointers to dereference. Applying batching to concurrent data structures is challenging, because it is difficult to maintain the search property and keep contention low in the presence of batching. In this paper, we present a general methodology for leveraging batching in concurrent search data structures, called BatchBoost. BatchBoost builds a search data structure from distinct "data" and "index" layers. The data layer’s purpose is to store a batch of key/value pairs in each of its nodes. The index layer uses an unmodified concurrent search data structure to route operations to a position in the data layer that is "close" to where the corresponding key should exist. The requirements on the index and data layers are low: with minimal effort, we were able to compose three highly scalable concurrent search data structures based on three original data structures as the index layers with a batched version of the Lazy List as the data layer. The resulting BatchBoost data structures provide significant performance improvements over their original counterparts. AU - Aksenov, Vitaly AU - Anoprenko, Michael AU - Fedorov, Alexander AU - Spear, Michael ID - 14485 SN - 1868-8969 T2 - 37th International Symposium on Distributed Computing TI - Brief announcement: BatchBoost: Universal batching for concurrent data structures VL - 281 ER - TY - JOUR AB - We present a minimal model of ferroelectric large polarons, which are suggested as one of the mechanisms responsible for the unique charge transport properties of hybrid perovskites. We demonstrate that short-ranged charge–rotor interactions lead to long-range ferroelectric ordering of rotors, which strongly affects the carrier mobility. In the nonperturbative regime, where our theory cannot be reduced to any of the earlier models, we reveal that the polaron is characterized by large coherence length and a roughly tenfold increase of the effective mass as compared to the bare mass. These results are in good agreement with other theoretical predictions for ferroelectric polarons. Our model establishes a general phenomenological framework for ferroelectric polarons providing the starting point for future studies of their role in the transport properties of hybrid organic-inorganic perovskites. AU - Koutentakis, Georgios AU - Ghazaryan, Areg AU - Lemeshko, Mikhail ID - 14486 IS - 4 JF - Physical Review Research SN - 2643-1564 TI - Rotor lattice model of ferroelectric large polarons VL - 5 ER - TY - JOUR AB - To respond to auxin, the chief orchestrator of their multicellularity, plants evolved multiple receptor systems and signal transduction cascades. Despite decades of research, however, we are still lacking a satisfactory synthesis of various auxin signaling mechanisms. The chief discrepancy and historical controversy of the field is that of rapid and slow auxin effects on plant physiology and development. How is it possible that ions begin to trickle across the plasma membrane as soon as auxin enters the cell, even though the best-characterized transcriptional auxin pathway can take effect only after tens of minutes? Recently, unexpected progress has been made in understanding this and other unknowns of auxin signaling. We provide a perspective on these exciting developments and concepts whose general applicability might have ramifications beyond auxin signaling. AU - Fiedler, Lukas AU - Friml, Jiří ID - 14313 IS - 10 JF - Current Opinion in Plant Biology SN - 1369-5266 TI - Rapid auxin signaling: Unknowns old and new VL - 75 ER - TY - GEN AB - We provide i) gridded initial conditions (.tif), ii) modeled gridded monthly outputs (.tif), and iii) modeled hourly outputs at the station locations (.txt) for the hydrological year 2019. Information about the variables and units can be found in the figures (.png) associated to each dataset. Details about the datasets can be found in the original publication by Buri and others (2023). Buri, P., Fatichi, S., Shaw, T. E., Miles, E. S., McCarthy, M. J., Fyffe, C. L., ... & Pellicciotti, F. (2023). Land Surface Modeling in the Himalayas: On the Importance of Evaporative Fluxes for the Water Balance of a High‐Elevation Catchment. Water Resources Research, 59(10), e2022WR033841. DOI: 10.1029/2022WR033841 AU - Buri, Pascal AU - Fatichi, Simone AU - Shaw, Thomas AU - Miles, Evan AU - McCarthy, Michael AU - Fyffe, Catriona Louise AU - Fugger, Stefan AU - Ren, Shaoting AU - Kneib, Marin AU - Jouberton, Achille AU - Steiner, Jakob AU - Fujita, Koji AU - Pellicciotti, Francesca ID - 14494 TI - Model output data to "Land surface modeling in the Himalayas: on the importance of evaporative fluxes for the water balance of a high elevation catchment" ER - TY - JOUR AB - An n-vertex graph is called C-Ramsey if it has no clique or independent set of size Clog2n (i.e., if it has near-optimal Ramsey behavior). In this paper, we study edge statistics in Ramsey graphs, in particular obtaining very precise control of the distribution of the number of edges in a random vertex subset of a C-Ramsey graph. This brings together two ongoing lines of research: the study of ‘random-like’ properties of Ramsey graphs and the study of small-ball probability for low-degree polynomials of independent random variables. The proof proceeds via an ‘additive structure’ dichotomy on the degree sequence and involves a wide range of different tools from Fourier analysis, random matrix theory, the theory of Boolean functions, probabilistic combinatorics and low-rank approximation. In particular, a key ingredient is a new sharpened version of the quadratic Carbery–Wright theorem on small-ball probability for polynomials of Gaussians, which we believe is of independent interest. One of the consequences of our result is the resolution of an old conjecture of Erdős and McKay, for which Erdős reiterated in several of his open problem collections and for which he offered one of his notorious monetary prizes. AU - Kwan, Matthew Alan AU - Sah, Ashwin AU - Sauermann, Lisa AU - Sawhney, Mehtaab ID - 14499 JF - Forum of Mathematics, Pi KW - Discrete Mathematics and Combinatorics KW - Geometry and Topology KW - Mathematical Physics KW - Statistics and Probability KW - Algebra and Number Theory KW - Analysis SN - 2050-5086 TI - Anticoncentration in Ramsey graphs and a proof of the Erdős–McKay conjecture VL - 11 ER - TY - JOUR AB - Cold atomic gases have become a paradigmatic system for exploring fundamental physics, which at the same time allows for applications in quantum technologies. The accelerating developments in the field have led to a highly advanced set of engineering techniques that, for example, can tune interactions, shape the external geometry, select among a large set of atomic species with different properties, or control the number of atoms. In particular, it is possible to operate in lower dimensions and drive atomic systems into the strongly correlated regime. In this review, we discuss recent advances in few-body cold atom systems confined in low dimensions from a theoretical viewpoint. We mainly focus on bosonic systems in one dimension and provide an introduction to the static properties before we review the state-of-the-art research into quantum dynamical processes stimulated by the presence of correlations. Besides discussing the fundamental physical phenomena arising in these systems, we also provide an overview of the calculational and numerical tools and methods that are commonly used, thus delivering a balanced and comprehensive overview of the field. We conclude by giving an outlook on possible future directions that are interesting to explore in these correlated systems. AU - Mistakidis, S. I. AU - Volosniev, Artem AU - Barfknecht, R. E. AU - Fogarty, T. AU - Busch, Th AU - Foerster, A. AU - Schmelcher, P. AU - Zinner, N. T. ID - 14513 JF - Physics Reports SN - 0370-1573 TI - Few-body Bose gases in low dimensions - A laboratory for quantum dynamics VL - 1042 ER - TY - DATA AB - We introduce a stochastic cellular automaton as a model for culture and border formation. The model can be conceptualized as a game where the expansion rate of cultures is quantified in terms of their area and perimeter in such a way that approximately round cultures get a competitive advantage. We first analyse the model with periodic boundary conditions, where we study how the model can end up in a fixed state, i.e. freezes. Then we implement the model on the European geography with mountains and rivers. We see how the model reproduces some qualitative features of European culture formation, namely that rivers and mountains are more frequently borders between cultures, mountainous regions tend to have higher cultural diversity and the central European plain has less clear cultural borders. AU - Klausen, Frederik Ravn AU - Lauritsen, Asbjørn Bækgaard ID - 12869 TI - Research data for: A stochastic cellular automaton model of culture formation ER - TY - JOUR AB - We introduce a stochastic cellular automaton as a model for culture and border formation. The model can be conceptualized as a game where the expansion rate of cultures is quantified in terms of their area and perimeter in such a way that approximately geometrically round cultures get a competitive advantage. We first analyze the model with periodic boundary conditions, where we study how the model can end up in a fixed state, i.e., freezes. Then we implement the model on the European geography with mountains and rivers. We see how the model reproduces some qualitative features of European culture formation, namely, that rivers and mountains are more frequently borders between cultures, mountainous regions tend to have higher cultural diversity, and the central European plain has less clear cultural borders. AU - Klausen, Frederik Ravn AU - Lauritsen, Asbjørn Bækgaard ID - 12890 IS - 5 JF - Physical Review E SN - 2470-0045 TI - Stochastic cellular automaton model of culture formation VL - 108 ER - TY - CONF AB - We revisit decentralized random beacons with a focus on practical distributed applications. Decentralized random beacons (Beaver and So, Eurocrypt'93) provide the functionality for n parties to generate an unpredictable sequence of bits in a way that cannot be biased, which is useful for any decentralized protocol requiring trusted randomness. Existing beacon constructions are highly inefficient in practical settings where protocol parties need to rejoin after crashes or disconnections, and more significantly where smart contracts may rely on arbitrary index points in high-volume streams. For this, we introduce a new notion of history-generating decentralized random beacons (HGDRBs). Roughly, the history-generation property of HGDRBs allows for previous beacon outputs to be efficiently generated knowing only the current value and the public key. At application layers, history-generation supports registering a sparser set of on-chain values if desired, so that apps like lotteries can utilize on-chain values without incurring high-frequency costs, enjoying all the benefits of DRBs implemented off-chain or with decoupled, special-purpose chains. Unlike rollups, HG is tailored specifically to recovering and verifying pseudorandom bit sequences and thus enjoys unique optimizations investigated in this work. We introduce STROBE: an efficient HGDRB construction which generalizes the original squaring-based RSA approach of Beaver and So. STROBE enjoys several useful properties that make it suited for practical applications that use beacons: 1) history-generating: it can regenerate and verify high-throughput beacon streams, supporting sparse (thus cost-effective) ledger entries; 2) concisely self-verifying: NIZK-free, with state and validation employing a single ring element; 3) eco-friendly: stake-based rather than work based; 4) unbounded: refresh-free, addressing limitations of Beaver and So; 5) delay-free: results are immediately available. 6) storage-efficient: the last beacon suffices to derive all past outputs, thus O(1) storage requirements for nodes serving the whole history. AU - Beaver, Donald AU - Kelkar, Mahimna AU - Lewi, Kevin AU - Nikolaenko, Valeria AU - Sonnino, Alberto AU - Chalkias, Konstantinos AU - Kokoris Kogias, Eleftherios AU - Naurois, Ladi De AU - Roy, Arnab ID - 14516 SN - 1868-8969 T2 - 5th Conference on Advances in Financial Technologies TI - STROBE: Streaming Threshold Random Beacons VL - 282 ER - TY - JOUR AB - State-of-the-art transmon qubits rely on large capacitors, which systematically improve their coherence due to reduced surface-loss participation. However, this approach increases both the footprint and the parasitic cross-coupling and is ultimately limited by radiation losses—a potential roadblock for scaling up quantum processors to millions of qubits. In this work we present transmon qubits with sizes as low as 36 × 39 µm2 with 100-nm-wide vacuum-gap capacitors that are micromachined from commercial silicon-on-insulator wafers and shadow evaporated with aluminum. We achieve a vacuum participation ratio up to 99.6% in an in-plane design that is compatible with standard coplanar circuits. Qubit relaxationtime measurements for small gaps with high zero-point electric field variance of up to 22 V/m reveal a double exponential decay indicating comparably strong qubit interaction with long-lived two-level systems. The exceptionally high selectivity of up to 20 dB to the superconductor-vacuum interface allows us to precisely back out the sub-single-photon dielectric loss tangent of aluminum oxide previously exposed to ambient conditions. In terms of future scaling potential, we achieve a ratio of qubit quality factor to a footprint area equal to 20 µm−2, which is comparable with the highest T1 devices relying on larger geometries, a value that could improve substantially for lower surface-loss superconductors. AU - Zemlicka, Martin AU - Redchenko, Elena AU - Peruzzo, Matilda AU - Hassani, Farid AU - Trioni, Andrea AU - Barzanjeh, Shabir AU - Fink, Johannes M ID - 14517 IS - 4 JF - Physical Review Applied TI - Compact vacuum-gap transmon qubits: Selective and sensitive probes for superconductor surface losses VL - 20 ER - TY - JOUR AB - Most natural and engineered information-processing systems transmit information via signals that vary in time. Computing the information transmission rate or the information encoded in the temporal characteristics of these signals requires the mutual information between the input and output signals as a function of time, i.e., between the input and output trajectories. Yet, this is notoriously difficult because of the high-dimensional nature of the trajectory space, and all existing techniques require approximations. We present an exact Monte Carlo technique called path weight sampling (PWS) that, for the first time, makes it possible to compute the mutual information between input and output trajectories for any stochastic system that is described by a master equation. The principal idea is to use the master equation to evaluate the exact conditional probability of an individual output trajectory for a given input trajectory and average this via Monte Carlo sampling in trajectory space to obtain the mutual information. We present three variants of PWS, which all generate the trajectories using the standard stochastic simulation algorithm. While direct PWS is a brute-force method, Rosenbluth-Rosenbluth PWS exploits the analogy between signal trajectory sampling and polymer sampling, and thermodynamic integration PWS is based on a reversible work calculation in trajectory space. PWS also makes it possible to compute the mutual information between input and output trajectories for systems with hidden internal states as well as systems with feedback from output to input. Applying PWS to the bacterial chemotaxis system, consisting of 182 coupled chemical reactions, demonstrates not only that the scheme is highly efficient but also that the number of receptor clusters is much smaller than hitherto believed, while their size is much larger. AU - Reinhardt, Manuel AU - Tkačik, Gašper AU - Ten Wolde, Pieter Rein ID - 14515 IS - 4 JF - Physical Review X TI - Path weight sampling: Exact Monte Carlo computation of the mutual information between stochastic trajectories VL - 13 ER - TY - JOUR AB - The elastic Leidenfrost effect occurs when a vaporizable soft solid is lowered onto a hot surface. Evaporative flow couples to elastic deformation, giving spontaneous bouncing or steady-state floating. The effect embodies an unexplored interplay between thermodynamics, elasticity, and lubrication: despite being observed, its basic theoretical description remains a challenge. Here, we provide a theory of elastic Leidenfrost floating. As weight increases, a rigid solid sits closer to the hot surface. By contrast, we discover an elasticity-dominated regime where the heavier the solid, the higher it floats. This geometry-governed behavior is reminiscent of the dynamics of large liquid Leidenfrost drops. We show that this elastic regime is characterized by Hertzian behavior of the solid’s underbelly and derive how the float height scales with materials parameters. Introducing a dimensionless elastic Leidenfrost number, we capture the crossover between rigid and Hertzian behavior. Our results provide theoretical underpinning for recent experiments, and point to the design of novel soft machines. AU - Binysh, Jack AU - Chakraborty, Indrajit AU - Chubynsky, Mykyta V. AU - Diaz Melian, Vicente L AU - Waitukaitis, Scott R AU - Sprittles, James E. AU - Souslov, Anton ID - 14514 IS - 16 JF - Physical Review Letters SN - 0031-9007 TI - Modeling Leidenfrost levitation of soft elastic solids VL - 131 ER - TY - GEN AB - see Readme file AU - Binysh, Jack AU - Chakraborty, Indrajit AU - Chubynsky, Mykyta AU - Diaz Melian, Vicente L AU - Waitukaitis, Scott R AU - Sprittles, James AU - Souslov, Anton ID - 14523 TI - SouslovLab/PRL2023-ModellingLeidenfrostLevitationofSoftElasticSolids: v1.0.1 ER - TY - CONF AB - We consider bidding games, a class of two-player zero-sum graph games. The game proceeds as follows. Both players have bounded budgets. A token is placed on a vertex of a graph, in each turn the players simultaneously submit bids, and the higher bidder moves the token, where we break bidding ties in favor of Player 1. Player 1 wins the game iff the token visits a designated target vertex. We consider, for the first time, poorman discrete-bidding in which the granularity of the bids is restricted and the higher bid is paid to the bank. Previous work either did not impose granularity restrictions or considered Richman bidding (bids are paid to the opponent). While the latter mechanisms are technically more accessible, the former is more appealing from a practical standpoint. Our study focuses on threshold budgets, which is the necessary and sufficient initial budget required for Player 1 to ensure winning against a given Player 2 budget. We first show existence of thresholds. In DAGs, we show that threshold budgets can be approximated with error bounds by thresholds under continuous-bidding and that they exhibit a periodic behavior. We identify closed-form solutions in special cases. We implement and experiment with an algorithm to find threshold budgets. AU - Avni, Guy AU - Meggendorfer, Tobias AU - Sadhukhan, Suman AU - Tkadlec, Josef AU - Zikelic, Dorde ID - 14518 SN - 0922-6389 T2 - Frontiers in Artificial Intelligence and Applications TI - Reachability poorman discrete-bidding games VL - 372 ER - TY - JOUR AB - Eukaryotic cells can undergo different forms of programmed cell death, many of which culminate in plasma membrane rupture as the defining terminal event1,2,3,4,5,6,7. Plasma membrane rupture was long thought to be driven by osmotic pressure, but it has recently been shown to be in many cases an active process, mediated by the protein ninjurin-18 (NINJ1). Here we resolve the structure of NINJ1 and the mechanism by which it ruptures membranes. Super-resolution microscopy reveals that NINJ1 clusters into structurally diverse assemblies in the membranes of dying cells, in particular large, filamentous assemblies with branched morphology. A cryo-electron microscopy structure of NINJ1 filaments shows a tightly packed fence-like array of transmembrane α-helices. Filament directionality and stability is defined by two amphipathic α-helices that interlink adjacent filament subunits. The NINJ1 filament features a hydrophilic side and a hydrophobic side, and molecular dynamics simulations show that it can stably cap membrane edges. The function of the resulting supramolecular arrangement was validated by site-directed mutagenesis. Our data thus suggest that, during lytic cell death, the extracellular α-helices of NINJ1 insert into the plasma membrane to polymerize NINJ1 monomers into amphipathic filaments that rupture the plasma membrane. The membrane protein NINJ1 is therefore an interactive component of the eukaryotic cell membrane that functions as an in-built breaking point in response to activation of cell death. AU - Degen, Morris AU - Santos, José Carlos AU - Pluhackova, Kristyna AU - Cebrero, Gonzalo AU - Ramos, Saray AU - Jankevicius, Gytis AU - Hartenian, Ella AU - Guillerm, Undina AU - Mari, Stefania A. AU - Kohl, Bastian AU - Müller, Daniel J. AU - Schanda, Paul AU - Maier, Timm AU - Perez, Camilo AU - Sieben, Christian AU - Broz, Petr AU - Hiller, Sebastian ID - 13096 JF - Nature SN - 0028-0836 TI - Structural basis of NINJ1-mediated plasma membrane rupture in cell death VL - 618 ER - TY - JOUR AB - A series of triarylamines was synthesised and screened for their suitability as catholytes in redox flow batteries using cyclic voltammetry (CV). Tris(4-aminophenyl)amine was found to be the strongest candidate. Solubility and initial electrochemical performance were promising; however, polymerisation was observed during electrochemical cycling leading to rapid capacity fade prescribed to a loss of accessible active material and the limitation of ion transport processes within the cell. A mixed electrolyte system of H3PO4 and HCl was found to inhibit polymerisation producing oligomers that consumed less active material reducing rates of degradation in the redox flow battery. Under these conditions Coulombic efficiency improved by over 4 %, the maximum number of cycles more than quadrupled and an additional theoretical capacity of 20 % was accessed. This paper is, to our knowledge, the first example of triarylamines as catholytes in all-aqueous redox flow batteries and emphasises the impact supporting electrolytes can have on electrochemical performance. AU - Farag, Nadia L. AU - Jethwa, Rajesh B AU - Beardmore, Alice E. AU - Insinna, Teresa AU - O'Keefe, Christopher A. AU - Klusener, Peter A.A. AU - Grey, Clare P. AU - Wright, Dominic S. ID - 13041 IS - 13 JF - ChemSusChem SN - 1864-5631 TI - Triarylamines as catholytes in aqueous organic redox flow batteries VL - 16 ER - TY - JOUR AB - Under high pressures and temperatures, molecular systems with substantial polarization charges, such as ammonia and water, are predicted to form superionic phases and dense fluid states with dissociating molecules and high electrical conductivity. This behaviour potentially plays a role in explaining the origin of the multipolar magnetic fields of Uranus and Neptune, whose mantles are thought to result from a mixture of H2O, NH3 and CH4 ices. Determining the stability domain, melting curve and electrical conductivity of these superionic phases is therefore crucial for modelling planetary interiors and dynamos. Here we report the melting curve of superionic ammonia up to 300 GPa from laser-driven shock compression of pre-compressed samples and atomistic calculations. We show that ammonia melts at lower temperatures than water above 100 GPa and that fluid ammonia’s electrical conductivity exceeds that of water at conditions predicted by hot, super-adiabatic models for Uranus and Neptune, and enhances the conductivity in their fluid water-rich dynamo layers. AU - Hernandez, J.-A. AU - Bethkenhagen, Mandy AU - Ninet, S. AU - French, M. AU - Benuzzi-Mounaix, A. AU - Datchi, F. AU - Guarguaglini, M. AU - Lefevre, F. AU - Occelli, F. AU - Redmer, R. AU - Vinci, T. AU - Ravasio, A. ID - 13118 JF - Nature Physics SN - 1745-2473 TI - Melting curve of superionic ammonia at planetary interior conditions VL - 19 ER - TY - JOUR AB - A density wave (DW) is a fundamental type of long-range order in quantum matter tied to self-organization into a crystalline structure. The interplay of DW order with superfluidity can lead to complex scenarios that pose a great challenge to theoretical analysis. In the past decades, tunable quantum Fermi gases have served as model systems for exploring the physics of strongly interacting fermions, including most notably magnetic ordering1, pairing and superfluidity2, and the crossover from a Bardeen–Cooper–Schrieffer superfluid to a Bose–Einstein condensate3. Here, we realize a Fermi gas featuring both strong, tunable contact interactions and photon-mediated, spatially structured long-range interactions in a transversely driven high-finesse optical cavity. Above a critical long-range interaction strength, DW order is stabilized in the system, which we identify via its superradiant light-scattering properties. We quantitatively measure the variation of the onset of DW order as the contact interaction is varied across the Bardeen–Cooper–Schrieffer superfluid and Bose–Einstein condensate crossover, in qualitative agreement with a mean-field theory. The atomic DW susceptibility varies over an order of magnitude upon tuning the strength and the sign of the long-range interactions below the self-ordering threshold, demonstrating independent and simultaneous control over the contact and long-range interactions. Therefore, our experimental setup provides a fully tunable and microscopically controllable platform for the experimental study of the interplay of superfluidity and DW order. AU - Helson, Victor AU - Zwettler, Timo AU - Mivehvar, Farokh AU - Colella, Elvia AU - Roux, Kevin Etienne Robert AU - Konishi, Hideki AU - Ritsch, Helmut AU - Brantut, Jean Philippe ID - 13119 JF - Nature SN - 0028-0836 TI - Density-wave ordering in a unitary Fermi gas with photon-mediated interactions VL - 618 ER - TY - JOUR AB - This paper establishes new connections between many-body quantum systems, One-body Reduced Density Matrices Functional Theory (1RDMFT) and Optimal Transport (OT), by interpreting the problem of computing the ground-state energy of a finite-dimensional composite quantum system at positive temperature as a non-commutative entropy regularized Optimal Transport problem. We develop a new approach to fully characterize the dual-primal solutions in such non-commutative setting. The mathematical formalism is particularly relevant in quantum chemistry: numerical realizations of the many-electron ground-state energy can be computed via a non-commutative version of Sinkhorn algorithm. Our approach allows to prove convergence and robustness of this algorithm, which, to our best knowledge, were unknown even in the two marginal case. Our methods are based on a priori estimates in the dual problem, which we believe to be of independent interest. Finally, the above results are extended in 1RDMFT setting, where bosonic or fermionic symmetry conditions are enforced on the problem. AU - Feliciangeli, Dario AU - Gerolin, Augusto AU - Portinale, Lorenzo ID - 12911 IS - 4 JF - Journal of Functional Analysis SN - 0022-1236 TI - A non-commutative entropic optimal transport approach to quantum composite systems at positive temperature VL - 285 ER - TY - JOUR AB - In this note we study the eigenvalue growth of infinite graphs with discrete spectrum. We assume that the corresponding Dirichlet forms satisfy certain Sobolev-type inequalities and that the total measure is finite. In this sense, the associated operators on these graphs display similarities to elliptic operators on bounded domains in the continuum. Specifically, we prove lower bounds on the eigenvalue growth and show by examples that corresponding upper bounds cannot be established. AU - Hua, Bobo AU - Keller, Matthias AU - Schwarz, Michael AU - Wirth, Melchior ID - 13177 IS - 8 JF - Proceedings of the American Mathematical Society SN - 0002-9939 TI - Sobolev-type inequalities and eigenvalue growth on graphs with finite measure VL - 151 ER - TY - JOUR AB - n the dynamic minimum set cover problem, the challenge is to minimize the update time while guaranteeing a close-to-optimal min{O(log n), f} approximation factor. (Throughout, n, m, f , and C are parameters denoting the maximum number of elements, the number of sets, the frequency, and the cost range.) In the high-frequency range, when f = Ω(log n) , this was achieved by a deterministic O(log n) -approximation algorithm with O(f log n) amortized update time by Gupta et al. [Online and dynamic algorithms for set cover, in Proceedings STOC 2017, ACM, pp. 537–550]. In this paper we consider the low-frequency range, when f = O(log n) , and obtain deterministic algorithms with a (1 + ∈)f -approximation ratio and the following guarantees on the update time. (1) O ((f/∈)-log(Cn)) amortized update time: Prior to our work, the best approximation ratio guaranteed by deterministic algorithms was O(f2) of Bhattacharya, Henzinger, and Italiano [Design of dynamic algorithms via primal-dual method, in Proceedings ICALP 2015, Springer, pp. 206–218]. In contrast, the only result with O(f) -approximation was that of Abboud et al. [Dynamic set cover: Improved algorithms and lower bounds, in Proceedings STOC 2019, ACM, pp. 114–125], who designed a randomized (1+∈)f -approximation algorithm with amortized update time. (2) O(f2/∈3 + (f/∈2).logC) amortized update time: This result improves the above update time bound for most values of f in the low-frequency range, i.e., f=o(log n) . It is also the first result that is independent of m and n. It subsumes the constant amortized update time of Bhattacharya and Kulkarni [Deterministically maintaining a (2 + ∈) -approximate minimum vertex cover in O(1/∈2) amortized update time, in Proceedings SODA 2019, SIAM, pp. 1872–1885] for unweighted dynamic vertex cover (i.e., when f = 2 and C = 1). (3) O((f/∈3).log2(Cn)) worst-case update time: No nontrivial worst-case update time was previously known for the dynamic set cover problem. Our bound subsumes and improves by a logarithmic factor the O(log3n/poly (∈)) worst-case update time for the unweighted dynamic vertex cover problem (i.e., when f = 2 and C =1) of Bhattacharya, Henzinger, and Nanongkai [Fully dynamic approximate maximum matching and minimum vertex cover in O(log3)n worst case update time, in Proceedings SODA 2017, SIAM, pp. 470–489]. We achieve our results via the primal-dual approach, by maintaining a fractional packing solution as a dual certificate. Prior work in dynamic algorithms that employs the primal-dual approach uses a local update scheme that maintains relaxed complementary slackness conditions for every set. For our first result we use instead a global update scheme that does not always maintain complementary slackness conditions. For our second result we combine the global and the local update schema. To achieve our third result we use a hierarchy of background schedulers. It is an interesting open question whether this background scheduler technique can also be used to transform algorithms with amortized running time bounds into algorithms with worst-case running time bounds. AU - Bhattacharya, Sayan AU - Henzinger, Monika H AU - Nanongkai, Danupon AU - Wu, Xiaowei ID - 14558 IS - 5 JF - SIAM Journal on Computing SN - 0097-5397 TI - Deterministic near-optimal approximation algorithms for dynamic set cover VL - 52 ER - TY - CONF AB - We consider the problem of learning control policies in discrete-time stochastic systems which guarantee that the system stabilizes within some specified stabilization region with probability 1. Our approach is based on the novel notion of stabilizing ranking supermartingales (sRSMs) that we introduce in this work. Our sRSMs overcome the limitation of methods proposed in previous works whose applicability is restricted to systems in which the stabilizing region cannot be left once entered under any control policy. We present a learning procedure that learns a control policy together with an sRSM that formally certifies probability 1 stability, both learned as neural networks. We show that this procedure can also be adapted to formally verifying that, under a given Lipschitz continuous control policy, the stochastic system stabilizes within some stabilizing region with probability 1. Our experimental evaluation shows that our learning procedure can successfully learn provably stabilizing policies in practice. AU - Ansaripour, Matin AU - Chatterjee, Krishnendu AU - Henzinger, Thomas A AU - Lechner, Mathias AU - Zikelic, Dorde ID - 14559 SN - 0302-9743 T2 - 21st International Symposium on Automated Technology for Verification and Analysis TI - Learning provably stabilizing neural controllers for discrete-time stochastic systems VL - 14215 ER - TY - JOUR AB - The Regularised Inertial Dean–Kawasaki model (RIDK) – introduced by the authors and J. Zimmer in earlier works – is a nonlinear stochastic PDE capturing fluctuations around the meanfield limit for large-scale particle systems in both particle density and momentum density. We focus on the following two aspects. Firstly, we set up a Discontinuous Galerkin (DG) discretisation scheme for the RIDK model: we provide suitable definitions of numerical fluxes at the interface of the mesh elements which are consistent with the wave-type nature of the RIDK model and grant stability of the simulations, and we quantify the rate of convergence in mean square to the continuous RIDK model. Secondly, we introduce modifications of the RIDK model in order to preserve positivity of the density (such a feature only holds in a “high-probability sense” for the original RIDK model). By means of numerical simulations, we show that the modifications lead to physically realistic and positive density profiles. In one case, subject to additional regularity constraints, we also prove positivity. Finally, we present an application of our methodology to a system of diffusing and reacting particles. Our Python code is available in open-source format. AU - Cornalba, Federico AU - Shardlow, Tony ID - 14554 IS - 5 JF - ESAIM: Mathematical Modelling and Numerical Analysis SN - 2822-7840 TI - The regularised inertial Dean' Kawasaki equation: Discontinuous Galerkin approximation and modelling for low-density regime VL - 57 ER - TY - JOUR AB - Inversions are structural mutations that reverse the sequence of a chromosome segment and reduce the effective rate of recombination in the heterozygous state. They play a major role in adaptation, as well as in other evolutionary processes such as speciation. Although inversions have been studied since the 1920s, they remain difficult to investigate because the reduced recombination conferred by them strengthens the effects of drift and hitchhiking, which in turn can obscure signatures of selection. Nonetheless, numerous inversions have been found to be under selection. Given recent advances in population genetic theory and empirical study, here we review how different mechanisms of selection affect the evolution of inversions. A key difference between inversions and other mutations, such as single nucleotide variants, is that the fitness of an inversion may be affected by a larger number of frequently interacting processes. This considerably complicates the analysis of the causes underlying the evolution of inversions. We discuss the extent to which these mechanisms can be disentangled, and by which approach. AU - Berdan, Emma L. AU - Barton, Nicholas H AU - Butlin, Roger AU - Charlesworth, Brian AU - Faria, Rui AU - Fragata, Inês AU - Gilbert, Kimberly J. AU - Jay, Paul AU - Kapun, Martin AU - Lotterhos, Katie E. AU - Mérot, Claire AU - Durmaz Mitchell, Esra AU - Pascual, Marta AU - Peichel, Catherine L. AU - Rafajlović, Marina AU - Westram, Anja M AU - Schaeffer, Stephen W. AU - Johannesson, Kerstin AU - Flatt, Thomas ID - 14556 JF - Journal of Evolutionary Biology SN - 1010-061X TI - How chromosomal inversions reorient the evolutionary process ER - TY - JOUR AB - The intricate regulatory processes behind actin polymerization play a crucial role in cellular biology, including essential mechanisms such as cell migration or cell division. However, the self-organizing principles governing actin polymerization are still poorly understood. In this perspective article, we compare the Belousov-Zhabotinsky (BZ) reaction, a classic and well understood chemical oscillator known for its self-organizing spatiotemporal dynamics, with the excitable dynamics of polymerizing actin. While the BZ reaction originates from the domain of inorganic chemistry, it shares remarkable similarities with actin polymerization, including the characteristic propagating waves, which are influenced by geometry and external fields, and the emergent collective behavior. Starting with a general description of emerging patterns, we elaborate on single droplets or cell-level dynamics, the influence of geometric confinements and conclude with collective interactions. Comparing these two systems sheds light on the universal nature of self-organization principles in both living and inanimate systems. AU - Riedl, Michael AU - Sixt, Michael K ID - 14555 JF - Frontiers in Cell and Developmental Biology TI - The excitable nature of polymerizing actin and the Belousov-Zhabotinsky reaction VL - 11 ER - TY - JOUR AB - The acyl-CoA-binding domain-containing protein 6 (ACBD6) is ubiquitously expressed, plays a role in the acylation of lipids and proteins, and regulates the N-myristoylation of proteins via N-myristoyltransferase enzymes (NMTs). However, its precise function in cells is still unclear, as is the consequence of ACBD6 defects on human pathophysiology. Utilizing exome sequencing and extensive international data sharing efforts, we identified 45 affected individuals from 28 unrelated families (consanguinity 93%) with bi-allelic pathogenic, predominantly loss-of-function (18/20) variants in ACBD6. We generated zebrafish and Xenopus tropicalis acbd6 knockouts by CRISPR/Cas9 and characterized the role of ACBD6 on protein N-myristoylation with YnMyr chemical proteomics in the model organisms and human cells, with the latter also being subjected further to ACBD6 peroxisomal localization studies. The affected individuals (23 males and 22 females), with ages ranging from 1 to 50 years old, typically present with a complex and progressive disease involving moderate-to-severe global developmental delay/intellectual disability (100%) with significant expressive language impairment (98%), movement disorders (97%), facial dysmorphism (95%), and mild cerebellar ataxia (85%) associated with gait impairment (94%), limb spasticity/hypertonia (76%), oculomotor (71%) and behavioural abnormalities (65%), overweight (59%), microcephaly (39%) and epilepsy (33%). The most conspicuous and common movement disorder was dystonia (94%), frequently leading to early-onset progressive postural deformities (97%), limb dystonia (55%), and cervical dystonia (31%). A jerky tremor in the upper limbs (63%), a mild head tremor (59%), parkinsonism/hypokinesia developing with advancing age (32%), and simple motor and vocal tics were among other frequent movement disorders. Midline brain malformations including corpus callosum abnormalities (70%), hypoplasia/agenesis of the anterior commissure (66%), short midbrain and small inferior cerebellar vermis (38% each), as well as hypertrophy of the clava (24%) were common neuroimaging findings. acbd6-deficient zebrafish and Xenopus models effectively recapitulated many clinical phenotypes reported in patients including movement disorders, progressive neuromotor impairment, seizures, microcephaly, craniofacial dysmorphism, and midbrain defects accompanied by developmental delay with increased mortality over time. Unlike ACBD5, ACBD6 did not show a peroxisomal localisation and ACBD6-deficiency was not associated with altered peroxisomal parameters in patient fibroblasts. Significant differences in YnMyr-labelling were observed for 68 co- and 18 post-translationally N-myristoylated proteins in patient-derived fibroblasts. N-Myristoylation was similarly affected in acbd6-deficient zebrafish and Xenopus tropicalis models, including Fus, Marcks, and Chchd-related proteins implicated in neurological diseases. The present study provides evidence that bi-allelic pathogenic variants in ACBD6 lead to a distinct neurodevelopmental syndrome accompanied by complex and progressive cognitive and movement disorders. AU - Kaiyrzhanov, Rauan AU - Rad, Aboulfazl AU - Lin, Sheng-Jia AU - Bertoli-Avella, Aida AU - Kallemeijn, Wouter W AU - Godwin, Annie AU - Zaki, Maha S AU - Huang, Kevin AU - Lau, Tracy AU - Petree, Cassidy AU - Efthymiou, Stephanie AU - Ghayoor Karimiani, Ehsan AU - Hempel, Maja AU - Normand, Elizabeth A AU - Rudnik-Schöneborn, Sabine AU - Schatz, Ulrich A AU - Baggelaar, Marc P AU - Ilyas, Muhammad AU - Sultan, Tipu AU - Alvi, Javeria Raza AU - Ganieva, Manizha AU - Fowler, Ben AU - Aanicai, Ruxandra AU - Akay Tayfun, Gulsen AU - Al Saman, Abdulaziz AU - Alswaid, Abdulrahman AU - Amiri, Nafise AU - Asilova, Nilufar AU - Shotelersuk, Vorasuk AU - Yeetong, Patra AU - Azam, Matloob AU - Babaei, Meisam AU - Bahrami Monajemi, Gholamreza AU - Mohammadi, Pouria AU - Samie, Saeed AU - Banu, Selina Husna AU - Basto, Jorge Pinto AU - Kortüm, Fanny AU - Bauer, Mislen AU - Bauer, Peter AU - Beetz, Christian AU - Garshasbi, Masoud AU - Hameed Issa, Awatif AU - Eyaid, Wafaa AU - Ahmed, Hind AU - Hashemi, Narges AU - Hassanpour, Kazem AU - Herman, Isabella AU - Ibrohimov, Sherozjon AU - Abdul-Majeed, Ban A AU - Imdad, Maria AU - Isrofilov, Maksudjon AU - Kaiyal, Qassem AU - Khan, Suliman AU - Kirmse, Brian AU - Koster, Janet AU - Lourenço, Charles Marques AU - Mitani, Tadahiro AU - Moldovan, Oana AU - Murphy, David AU - Najafi, Maryam AU - Pehlivan, Davut AU - Rocha, Maria Eugenia AU - Salpietro, Vincenzo AU - Schmidts, Miriam AU - Shalata, Adel AU - Mahroum, Mohammad AU - Talbeya, Jawabreh Kassem AU - Taylor, Robert W AU - Vazquez, Dayana AU - Vetro, Annalisa AU - Waterham, Hans R AU - Zaman, Mashaya AU - Schrader, Tina A AU - Chung, Wendy K AU - Guerrini, Renzo AU - Lupski, James R AU - Gleeson, Joseph AU - Suri, Mohnish AU - Jamshidi, Yalda AU - Bhatia, Kailash P AU - Vona, Barbara AU - Schrader, Michael AU - Severino, Mariasavina AU - Guille, Matthew AU - Tate, Edward W AU - Varshney, Gaurav K AU - Houlden, Henry AU - Maroofian, Reza ID - 14543 JF - Brain KW - Neurology (clinical) SN - 0006-8950 TI - Bi-allelic ACBD6 variants lead to a neurodevelopmental syndrome with progressive and complex movement disorders ER - TY - JOUR AB - It is a remarkable property of BCS theory that the ratio of the energy gap at zero temperature Ξ and the critical temperature Tc is (approximately) given by a universal constant, independent of the microscopic details of the fermionic interaction. This universality has rigorously been proven quite recently in three spatial dimensions and three different limiting regimes: weak coupling, low density and high density. The goal of this short note is to extend the universal behavior to lower dimensions d=1,2 and give an exemplary proof in the weak coupling limit. AU - Henheik, Sven Joscha AU - Lauritsen, Asbjørn Bækgaard AU - Roos, Barbara ID - 14542 JF - Reviews in Mathematical Physics SN - 0129-055X TI - Universality in low-dimensional BCS theory ER - TY - JOUR AB - Quantum state tomography is an essential component of modern quantum technology. In application to continuous-variable harmonic-oscillator systems, such as the electromagnetic field, existing tomography methods typically reconstruct the state in discrete bases, and are hence limited to states with relatively low amplitudes and energies. Here, we overcome this limitation by utilizing a feed-forward neural network to obtain the density matrix directly in the continuous position basis. An important benefit of our approach is the ability to choose specific regions in the phase space for detailed reconstruction. This results in a relatively slow scaling of the amount of resources required for the reconstruction with the state amplitude, and hence allows us to dramatically increase the range of amplitudes accessible with our method. AU - Fedotova, Ekaterina AU - Kuznetsov, Nikolai AU - Tiunov, Egor AU - Ulanov, A. E. AU - Lvovsky, A. I. ID - 14553 IS - 4 JF - Physical Review A SN - 2469-9926 TI - Continuous-variable quantum tomography of high-amplitude states VL - 108 ER - TY - JOUR AB - Motivated by a problem posed in [10], we investigate the closure operators of the category SLatt of join semilattices and its subcategory SLattO of join semilattices with bottom element. In particular, we show that there are only finitely many closure operators of both categories, and provide a complete classification. We use this result to deduce the known fact that epimorphisms of SLatt and SLattO are surjective. We complement the paper with two different proofs of this result using either generators or Isbell’s zigzag theorem. AU - Dikranjan, D. AU - Giordano Bruno, A. AU - Zava, Nicolò ID - 14557 IS - S1 JF - Quaestiones Mathematicae SN - 1607-3606 TI - Epimorphisms and closure operators of categories of semilattices VL - 46 ER - TY - JOUR AB - Interactions between plants and herbivores are central in most ecosystems, but their strength is highly variable. The amount of variability within a system is thought to influence most aspects of plant-herbivore biology, from ecological stability to plant defense evolution. Our understanding of what influences variability, however, is limited by sparse data. We collected standardized surveys of herbivory for 503 plant species at 790 sites across 116° of latitude. With these data, we show that within-population variability in herbivory increases with latitude, decreases with plant size, and is phylogenetically structured. Differences in the magnitude of variability are thus central to how plant-herbivore biology varies across macroscale gradients. We argue that increased focus on interaction variability will advance understanding of patterns of life on Earth. AU - Robinson, M. L. AU - Hahn, P. G. AU - Inouye, B. D. AU - Underwood, N. AU - Whitehead, S. R. AU - Abbott, K. C. AU - Bruna, E. M. AU - Cacho, N. I. AU - Dyer, L. A. AU - Abdala-Roberts, L. AU - Allen, W. J. AU - Andrade, J. F. AU - Angulo, D. F. AU - Anjos, D. AU - Anstett, D. N. AU - Bagchi, R. AU - Bagchi, S. AU - Barbosa, M. AU - Barrett, S. AU - Baskett, Carina AU - Ben-Simchon, E. AU - Bloodworth, K. J. AU - Bronstein, J. L. AU - Buckley, Y. M. AU - Burghardt, K. T. AU - Bustos-Segura, C. AU - Calixto, E. S. AU - Carvalho, R. L. AU - Castagneyrol, B. AU - Chiuffo, M. C. AU - Cinoğlu, D. AU - Cinto Mejía, E. AU - Cock, M. C. AU - Cogni, R. AU - Cope, O. L. AU - Cornelissen, T. AU - Cortez, D. R. AU - Crowder, D. W. AU - Dallstream, C. AU - Dáttilo, W. AU - Davis, J. K. AU - Dimarco, R. D. AU - Dole, H. E. AU - Egbon, I. N. AU - Eisenring, M. AU - Ejomah, A. AU - Elderd, B. D. AU - Endara, M. J. AU - Eubanks, M. D. AU - Everingham, S. E. AU - Farah, K. N. AU - Farias, R. P. AU - Fernandes, A. P. AU - Fernandes, G. W. AU - Ferrante, M. AU - Finn, A. AU - Florjancic, G. A. AU - Forister, M. L. AU - Fox, Q. N. AU - Frago, E. AU - França, F. M. AU - Getman-Pickering, A. S. AU - Getman-Pickering, Z. AU - Gianoli, E. AU - Gooden, B. AU - Gossner, M. M. AU - Greig, K. A. AU - Gripenberg, S. AU - Groenteman, R. AU - Grof-Tisza, P. AU - Haack, N. AU - Hahn, L. AU - Haq, S. M. AU - Helms, A. M. AU - Hennecke, J. AU - Hermann, S. L. AU - Holeski, L. M. AU - Holm, S. AU - Hutchinson, M. C. AU - Jackson, E. E. AU - Kagiya, S. AU - Kalske, A. AU - Kalwajtys, M. AU - Karban, R. AU - Kariyat, R. AU - Keasar, T. AU - Kersch-Becker, M. F. AU - Kharouba, H. M. AU - Kim, T. N. AU - Kimuyu, D. M. AU - Kluse, J. AU - Koerner, S. E. AU - Komatsu, K. J. AU - Krishnan, S. AU - Laihonen, M. AU - Lamelas-López, L. AU - Lascaleia, M. C. AU - Lecomte, N. AU - Lehn, C. R. AU - Li, X. AU - Lindroth, R. L. AU - Lopresti, E. F. AU - Losada, M. AU - Louthan, A. M. AU - Luizzi, V. J. AU - Lynch, S. C. AU - Lynn, J. S. AU - Lyon, N. J. AU - Maia, L. F. AU - Maia, R. A. AU - Mannall, T. L. AU - Martin, B. S. AU - Massad, T. J. AU - Mccall, A. C. AU - Mcgurrin, K. AU - Merwin, A. C. AU - Mijango-Ramos, Z. AU - Mills, C. H. AU - Moles, A. T. AU - Moore, C. M. AU - Moreira, X. AU - Morrison, C. R. AU - Moshobane, M. C. AU - Muola, A. AU - Nakadai, R. AU - Nakajima, K. AU - Novais, S. AU - Ogbebor, C. O. AU - Ohsaki, H. AU - Pan, V. S. AU - Pardikes, N. A. AU - Pareja, M. AU - Parthasarathy, N. AU - Pawar, R. R. AU - Paynter, Q. AU - Pearse, I. S. AU - Penczykowski, R. M. AU - Pepi, A. A. AU - Pereira, C. C. AU - Phartyal, S. S. AU - Piper, F. I. AU - Poveda, K. AU - Pringle, E. G. AU - Puy, J. AU - Quijano, T. AU - Quintero, C. AU - Rasmann, S. AU - Rosche, C. AU - Rosenheim, L. Y. AU - Rosenheim, J. A. AU - Runyon, J. B. AU - Sadeh, A. AU - Sakata, Y. AU - Salcido, D. M. AU - Salgado-Luarte, C. AU - Santos, B. A. AU - Sapir, Y. AU - Sasal, Y. AU - Sato, Y. AU - Sawant, M. AU - Schroeder, H. AU - Schumann, I. AU - Segoli, M. AU - Segre, H. AU - Shelef, O. AU - Shinohara, N. AU - Singh, R. P. AU - Smith, D. S. AU - Sobral, M. AU - Stotz, G. C. AU - Tack, A. J.M. AU - Tayal, M. AU - Tooker, J. F. AU - Torrico-Bazoberry, D. AU - Tougeron, K. AU - Trowbridge, A. M. AU - Utsumi, S. AU - Uyi, O. AU - Vaca-Uribe, J. L. AU - Valtonen, A. AU - Van Dijk, L. J.A. AU - Vandvik, V. AU - Villellas, J. AU - Waller, L. P. AU - Weber, M. G. AU - Yamawo, A. AU - Yim, S. AU - Zarnetske, P. L. AU - Zehr, L. N. AU - Zhong, Z. AU - Wetzel, W. C. ID - 14552 IS - 6671 JF - Science TI - Plant size, latitude, and phylogeny explain within-population variability in herbivory VL - 382 ER - TY - JOUR AB - Methylation of CG dinucleotides (mCGs), which regulates eukaryotic genome functions, is epigenetically propagated by Dnmt1/MET1 methyltransferases. How mCG is established and transmitted across generations despite imperfect enzyme fidelity is unclear. Whether mCG variation in natural populations is governed by genetic or epigenetic inheritance also remains mysterious. Here, we show that MET1 de novo activity, which is enhanced by existing proximate methylation, seeds and stabilizes mCG in Arabidopsis thaliana genes. MET1 activity is restricted by active demethylation and suppressed by histone variant H2A.Z, producing localized mCG patterns. Based on these observations, we develop a stochastic mathematical model that precisely recapitulates mCG inheritance dynamics and predicts intragenic mCG patterns and their population-scale variation given only CG site spacing. Our results demonstrate that intragenic mCG establishment, inheritance, and variance constitute a unified epigenetic process, revealing that intragenic mCG undergoes large, millennia-long epigenetic fluctuations and can therefore mediate evolution on this timescale. AU - Briffa, Amy AU - Hollwey, Elizabeth AU - Shahzad, Zaigham AU - Moore, Jonathan D. AU - Lyons, David B. AU - Howard, Martin AU - Zilberman, Daniel ID - 14551 IS - 11 JF - Cell Systems SN - 2405-4712 TI - Millennia-long epigenetic fluctuations generate intragenic DNA methylation variance in Arabidopsis populations VL - 14 ER - TY - GEN AB - This is associated with our paper "Plant size, latitude, and phylogeny explain within-population variability in herbivory" published in Science. AU - Wetzel, William ID - 14579 TI - HerbVar-Network/HV-Large-Patterns-MS-public: v1.0.0 ER - TY - JOUR AB - Regulation of the Arp2/3 complex is required for productive nucleation of branched actin networks. An emerging aspect of regulation is the incorporation of subunit isoforms into the Arp2/3 complex. Specifically, both ArpC5 subunit isoforms, ArpC5 and ArpC5L, have been reported to fine-tune nucleation activity and branch junction stability. We have combined reverse genetics and cellular structural biology to describe how ArpC5 and ArpC5L differentially affect cell migration. Both define the structural stability of ArpC1 in branch junctions and, in turn, by determining protrusion characteristics, affect protein dynamics and actin network ultrastructure. ArpC5 isoforms also affect the positioning of members of the Ena/Vasodilator-stimulated phosphoprotein (VASP) family of actin filament elongators, which mediate ArpC5 isoform–specific effects on the actin assembly level. Our results suggest that ArpC5 and Ena/VASP proteins are part of a signaling pathway enhancing cell migration. AU - Fäßler, Florian AU - Javoor, Manjunath AU - Datler, Julia AU - Döring, Hermann AU - Hofer, Florian AU - Dimchev, Georgi A AU - Hodirnau, Victor-Valentin AU - Faix, Jan AU - Rottner, Klemens AU - Schur, Florian KM ID - 12334 IS - 3 JF - Science Advances KW - Multidisciplinary SN - 2375-2548 TI - ArpC5 isoforms regulate Arp2/3 complex–dependent protrusion through differential Ena/VASP positioning VL - 9 ER - TY - DATA AB - Regulation of the Arp2/3 complex is required for productive nucleation of branched actin networks. An emerging aspect of regulation is the incorporation of subunit isoforms into the Arp2/3 complex. Specifically, both ArpC5 subunit isoforms, ArpC5 and ArpC5L, have been reported to fine-tune nucleation activity and branch junction stability. We have combined reverse genetics and cellular structural biology to describe how ArpC5 and ArpC5L differentially affect cell migration. Both define the structural stability of ArpC1 in branch junctions and, in turn, by determining protrusion characteristics, affect protein dynamics and actin network ultrastructure. ArpC5 isoforms also affect the positioning of members of the Ena/Vasodilator-stimulated phosphoprotein (VASP) family of actin filament elongators, which mediate ArpC5 isoform–specific effects on the actin assembly level. Our results suggest that ArpC5 and Ena/VASP proteins are part of a signaling pathway enhancing cell migration. AU - Schur, Florian KM ID - 14562 TI - Research data of the publication "ArpC5 isoforms regulate Arp2/3 complex-dependent protrusion through differential Ena/VASP positioning" ER - TY - COMP AB - A precise quantitative description of the ultrastructural characteristics underlying biological mechanisms is often key to their understanding. This is particularly true for dynamic extra- and intracellular filamentous assemblies, playing a role in cell motility, cell integrity, cytokinesis, tissue formation and maintenance. For example, genetic manipulation or modulation of actin regulatory proteins frequently manifests in changes of the morphology, dynamics, and ultrastructural architecture of actin filament-rich cell peripheral structures, such as lamellipodia or filopodia. However, the observed ultrastructural effects often remain subtle and require sufficiently large datasets for appropriate quantitative analysis. The acquisition of such large datasets has been enabled by recent advances in high-throughput cryo-electron tomography (cryo-ET) methods. This also necessitates the development of complementary approaches to maximize the extraction of relevant biological information. We have developed a computational toolbox for the semi-automatic quantification of segmented and vectorized fila- mentous networks from pre-processed cryo-electron tomograms, facilitating the analysis and cross-comparison of multiple experimental conditions. GUI-based components simplify the processing of data and allow users to obtain a large number of ultrastructural parameters describing filamentous assemblies. We demonstrate the feasibility of this workflow by analyzing cryo-ET data of untreated and chemically perturbed branched actin filament networks and that of parallel actin filament arrays. In principle, the computational toolbox presented here is applicable for data analysis comprising any type of filaments in regular (i.e. parallel) or random arrangement. We show that it can ease the identification of key differences between experimental groups and facilitate the in-depth analysis of ultrastructural data in a time-efficient manner. AU - Dimchev, Georgi A AU - Amiri, Behnam AU - Fäßler, Florian AU - Falcke, Martin AU - Schur, Florian KM ID - 14502 KW - cryo-electron tomography KW - actin cytoskeleton KW - toolbox TI - Computational toolbox for ultrastructural quantitative analysis of filament networks in cryo-ET data ER - TY - JOUR AB - Motile cells moving in multicellular organisms encounter microenvironments of locally heterogeneous mechanochemical composition. Individual compositional parameters like chemotactic signals, adhesiveness, and pore sizes are well known to be sensed by motile cells, providing individual guidance cues for cellular pathfinding. However, motile cells encounter diverse mechanochemical signals at the same time, raising the question of how cells respond to locally diverse and potentially competing signals on their migration routes. Here, we reveal that motile amoeboid cells require nuclear repositioning, termed nucleokinesis, for adaptive pathfinding in heterogeneous mechanochemical microenvironments. Using mammalian immune cells and the amoebaDictyostelium discoideum, we discover that frequent, rapid and long-distance nucleokinesis is a basic component of amoeboid pathfinding, enabling cells to reorientate quickly between locally competing cues. Amoeboid nucleokinesis comprises a two-step cell polarity switch and is driven by myosin II-forces, sliding the nucleus from a ‘losing’ to the ‘winning’ leading edge to re-adjust the nuclear to the cellular path. Impaired nucleokinesis distorts fast path adaptions and causes cellular arrest in the microenvironment. Our findings establish that nucleokinesis is required for amoeboid cell navigation. Given that motile single-cell amoebae, many immune cells, and some cancer cells utilize an amoeboid migration strategy, these results suggest that amoeboid nucleokinesis underlies cellular navigation during unicellular biology, immunity, and disease. AU - Kroll, Janina AU - Hauschild, Robert AU - Kuznetcov, Arthur AU - Stefanowski, Kasia AU - Hermann, Monika D. AU - Merrin, Jack AU - Shafeek, Lubuna B AU - Müller-Taubenberger, Annette AU - Renkawitz, Jörg ID - 13342 JF - EMBO Journal SN - 0261-4189 TI - Adaptive pathfinding by nucleokinesis during amoeboid migration ER - TY - JOUR AB - AbstractEndomembrane damage represents a form of stress that is detrimental for eukaryotic cells1,2. To cope with this threat, cells possess mechanisms that repair the damage and restore cellular homeostasis3–7. Endomembrane damage also results in organelle instability and the mechanisms by which cells stabilize damaged endomembranes to enable membrane repair remains unknown. Here, by combining in vitro and in cellulo studies with computational modelling we uncover a biological function for stress granules whereby these biomolecular condensates form rapidly at endomembrane damage sites and act as a plug that stabilizes the ruptured membrane. Functionally, we demonstrate that stress granule formation and membrane stabilization enable efficient repair of damaged endolysosomes, through both ESCRT (endosomal sorting complex required for transport)-dependent and independent mechanisms. We also show that blocking stress granule formation in human macrophages creates a permissive environment for Mycobacterium tuberculosis, a human pathogen that exploits endomembrane damage to survive within the host. AU - Bussi, Claudio AU - Mangiarotti, Agustín AU - Vanhille-Campos, Christian Eduardo AU - Aylan, Beren AU - Pellegrino, Enrica AU - Athanasiadi, Natalia AU - Fearns, Antony AU - Rodgers, Angela AU - Franzmann, Titus M. AU - Šarić, Anđela AU - Dimova, Rumiana AU - Gutierrez, Maximiliano G. ID - 14610 JF - Nature KW - Multidisciplinary SN - 0028-0836 TI - Stress granules plug and stabilize damaged endolysosomal membranes ER - TY - DATA AB - Data related to the following paper: "Stress granules plug and stabilize damaged endolysosomal membranes" (https://doi.org/10.1038/s41586-023-06726-w) Abstract: Endomembrane damage represents a form of stress that is detrimental for eukaryotic cells. To cope with this threat, cells possess mechanisms that repair the damage and restore cellular homeostasis. Endomembrane damage also results in organelle instability and the mechanisms by which cells stabilize damaged endomembranes to enable membrane repair remains unknown. In this work we use a minimal coarse-grained molecular dynamics system to explore how lipid vesicles undergoing poration in a protein-rich medium can be plugged and stabilised by condensate formation. The solution of proteins in and out of the vesicle is described by beads dispersed in implicit solvent. The membrane is described as a one-bead-thick fluid elastic layer of mechanical properties that mimic biological membranes. We tune the interactions between solution beads in the different compartments to capture the differences between the cytoplasmic and endosomal protein solutions and explore how the system responds to different degrees of membrane poration. We find that, in the right interaction regime, condensates form rapidly at the damage site upon solution mixing and act as a plug that prevents futher mixing and destabilisation of the vesicle. Further, when the condensate can interact with the membrane (wetting interactions) we find that it mediates pore sealing and membrane repair. This research is part of the work published in "Stress granules plug and stabilize damaged endolysosomal membranes", Bussi et al, Nature, 2023 - 10.1038/s41586-023-06726-w. AU - Vanhille-Campos, Christian Eduardo AU - Šarić, Anđela ID - 14472 TI - Stress granules plug and stabilize damaged endolysosomal membranes ER - TY - JOUR AB - Muscle degeneration is the most prevalent cause for frailty and dependency in inherited diseases and ageing. Elucidation of pathophysiological mechanisms, as well as effective treatments for muscle diseases, represents an important goal in improving human health. Here, we show that the lipid synthesis enzyme phosphatidylethanolamine cytidyltransferase (PCYT2/ECT) is critical to muscle health. Human deficiency in PCYT2 causes a severe disease with failure to thrive and progressive weakness. pcyt2-mutant zebrafish and muscle-specific Pcyt2-knockout mice recapitulate the participant phenotypes, with failure to thrive, progressive muscle weakness and accelerated ageing. Mechanistically, muscle Pcyt2 deficiency affects cellular bioenergetics and membrane lipid bilayer structure and stability. PCYT2 activity declines in ageing muscles of mice and humans, and adeno-associated virus-based delivery of PCYT2 ameliorates muscle weakness in Pcyt2-knockout and old mice, offering a therapy for individuals with a rare disease and muscle ageing. Thus, PCYT2 plays a fundamental and conserved role in vertebrate muscle health, linking PCYT2 and PCYT2-synthesized lipids to severe muscle dystrophy and ageing. AU - Cikes, Domagoj AU - Elsayad, Kareem AU - Sezgin, Erdinc AU - Koitai, Erika AU - Ferenc, Torma AU - Orthofer, Michael AU - Yarwood, Rebecca AU - Heinz, Leonhard X. AU - Sedlyarov, Vitaly AU - Darwish-Miranda, Nasser AU - Taylor, Adrian AU - Grapentine, Sophie AU - al-Murshedi, Fathiya AU - Abot, Anne AU - Weidinger, Adelheid AU - Kutchukian, Candice AU - Sanchez, Colline AU - Cronin, Shane J. F. AU - Novatchkova, Maria AU - Kavirayani, Anoop AU - Schuetz, Thomas AU - Haubner, Bernhard AU - Haas, Lisa AU - Hagelkruys, Astrid AU - Jackowski, Suzanne AU - Kozlov, Andrey AU - Jacquemond, Vincent AU - Knauf, Claude AU - Superti-Furga, Giulio AU - Rullman, Eric AU - Gustafsson, Thomas AU - McDermot, John AU - Lowe, Martin AU - Radak, Zsolt AU - Chamberlain, Jeffrey S. AU - Bakovic, Marica AU - Banka, Siddharth AU - Penninger, Josef M. ID - 12747 JF - Nature Metabolism KW - Cell Biology KW - Physiology (medical) KW - Endocrinology KW - Diabetes and Metabolism KW - Internal Medicine SN - 2522-5812 TI - PCYT2-regulated lipid biosynthesis is critical to muscle health and ageing VL - 5 ER - TY - JOUR AB - The phonon transport mechanisms and ultralow lattice thermal conductivities (κL) in silver halide AgX (X=Cl,Br,I) compounds are not yet well understood. Herein, we study the lattice dynamics and thermal property of AgX under the framework of perturbation theory and the two-channel Wigner thermal transport model based on accurate machine learning potentials. We find that an accurate extraction of the third-order atomic force constants from largely displaced configurations is significant for the calculation of the κL of AgX, and the coherence thermal transport is also non-negligible. In AgI, however, the calculated κL still considerably overestimates the experimental values even including four-phonon scatterings. Molecular dynamics (MD) simulations using machine learning potential suggest an important role of the higher-than-fourth-order lattice anharmonicity in the low-frequency phonon linewidths of AgI at room temperature, which can be related to the simultaneous restrictions of the three- and four-phonon phase spaces. The κL of AgI calculated using MD phonon lifetimes including full-order lattice anharmonicity shows a better agreement with experiments. AU - Ouyang, Niuchang AU - Zeng, Zezhu AU - Wang, Chen AU - Wang, Qi AU - Chen, Yue ID - 14605 IS - 17 JF - Physical Review B SN - 2469-9950 TI - Role of high-order lattice anharmonicity in the phonon thermal transport of silver halide AgX (X=Cl,Br, I) VL - 108 ER - TY - CONF AB - Distributed Key Generation (DKG) is a technique to bootstrap threshold cryptosystems without a trusted party. DKG is an essential building block to many decentralized protocols such as randomness beacons, threshold signatures, Byzantine consensus, and multiparty computation. While significant progress has been made recently, existing asynchronous DKG constructions are inefficient when the reconstruction threshold is larger than one-third of the total nodes. In this paper, we present a simple and concretely efficient asynchronous DKG (ADKG) protocol among n = 3t + 1 nodes that can tolerate up to t malicious nodes and support any reconstruction threshold ℓ ≥ t. Our protocol has an expected O(κn3) communication cost, where κ is the security parameter, and only assumes the hardness of the Discrete Logarithm. The core ingredient of our ADKG protocol is an asynchronous protocol to secret share a random polynomial of degree ℓ ≥ t, which has other applications, such as asynchronous proactive secret sharing and asynchronous multiparty computation. We implement our high-threshold ADKG protocol and evaluate it using a network of up to 128 geographically distributed nodes. Our evaluation shows that our high-threshold ADKG protocol reduces the running time by 90% and bandwidth usage by 80% over the state-of-the-art. AU - Das, Sourav AU - Xiang, Zhuolun AU - Kokoris Kogias, Eleftherios AU - Ren, Ling ID - 14609 SN - 9781713879497 T2 - 32nd USENIX Security Symposium TI - Practical asynchronous high-threshold distributed key generation and distributed polynomial sampling VL - 8 ER - TY - JOUR AB - Computing the solubility of crystals in a solvent using atomistic simulations is notoriously challenging due to the complexities and convergence issues associated with free-energy methods, as well as the slow equilibration in direct-coexistence simulations. This paper introduces a molecular-dynamics workflow that simplifies and robustly computes the solubility of molecular or ionic crystals. This method is considerably more straightforward than the state-of-the-art, as we have streamlined and optimised each step of the process. Specifically, we calculate the chemical potential of the crystal using the gas-phase molecule as a reference state, and employ the S0 method to determine the concentration dependence of the chemical potential of the solute. We use this workflow to predict the solubilities of sodium chloride in water, urea polymorphs in water, and paracetamol polymorphs in both water and ethanol. Our findings indicate that the predicted solubility is sensitive to the chosen potential energy surface. Furthermore, we note that the harmonic approximation often fails for both molecular crystals and gas molecules at or above room temperature, and that the assumption of an ideal solution becomes less valid for highly soluble substances. AU - Reinhardt, Aleks AU - Chew, Pin Yu AU - Cheng, Bingqing ID - 14603 IS - 18 JF - Journal of Chemical Physics SN - 0021-9606 TI - A streamlined molecular-dynamics workflow for computing solubilities of molecular and ionic crystals VL - 159 ER - TY - JOUR AB - Sex chromosomes have evolved independently multiple times, but why some are conserved for more than 100 million years whereas others turnover rapidly remains an open question. Here, we examine the homology of sex chromosomes across nine orders of insects, plus the outgroup springtails. We find that the X chromosome is likely homologous across insects and springtails; the only exception is in the Lepidoptera, which has lost the X and now has a ZZ/ZW sex-chromosome system. These results suggest the ancestral insect X chromosome has persisted for more than 450 million years—the oldest known sex chromosome to date. Further, we propose that the shrinking of gene content the dipteran X chromosome has allowed for a burst of sex-chromosome turnover that is absent from other speciose insect orders. AU - Toups, Melissa A AU - Vicoso, Beatriz ID - 14604 IS - 11 JF - Evolution TI - The X chromosome of insects likely predates the origin of class Insecta VL - 77 ER - TY - GEN AB - Sex chromosomes have evolved independently multiple times, but why some are conserved for more than 100 million years whereas others turnover rapidly remains an open question. Here, we examine the homology of sex chromosomes across nine orders of insects, plus the outgroup springtails. We find that the X chromosome is likely homologous across insects and springtails; the only exception is in the Lepidoptera, which has lost the X and now has a ZZ/ZW sex chromosome system. These results suggest the ancestral insect X chromosome has persisted for more than 450 million years – the oldest known sex chromosome to date. Further, we propose that the shrinking of gene content of the Dipteran X chromosome has allowed for a burst of sex-chromosome turnover that is absent from other speciose insect orders. AU - Toups, Melissa A AU - Vicoso, Beatriz ID - 14616 TI - The X chromosome of insects likely predates the origin of Class Insecta ER - TY - GEN AB - Sex chromosomes have evolved independently multiple times, but why some are conserved for more than 100 million years whereas others turnover rapidly remains an open question. Here, we examine the homology of sex chromosomes across nine orders of insects, plus the outgroup springtails. We find that the X chromosome is likely homologous across insects and springtails; the only exception is in the Lepidoptera, which has lost the X and now has a ZZ/ZW sex chromosome system. These results suggest the ancestral insect X chromosome has persisted for more than 450 million years – the oldest known sex chromosome to date. Further, we propose that the shrinking of gene content of the Dipteran X chromosome has allowed for a burst of sex-chromosome turnover that is absent from other speciose insect orders. AU - Toups, Melissa A AU - Vicoso, Beatriz ID - 14617 TI - The X chromosome of insects likely predates the origin of Class Insecta ER - TY - GEN AB - Data underlying the publication "A streamlined molecular-dynamics workflow for computing solubilities of molecular and ionic crystals" (DOI https://doi.org/10.1063/5.0173341). AU - Cheng, Bingqing ID - 14619 TI - BingqingCheng/solubility: V1.0 ER - TY - JOUR AB - Cumulus parameterization (CP) in state‐of‐the‐art global climate models is based on the quasi‐equilibrium assumption (QEA), which views convection as the action of an ensemble of cumulus clouds, in a state of equilibrium with respect to a slowly varying atmospheric state. This view is not compatible with the organization and dynamical interactions across multiple scales of cloud systems in the tropics and progress in this research area was slow over decades despite the widely recognized major shortcomings. Novel ideas on how to represent key physical processes of moist convection‐large‐scale interaction to overcome the QEA have surged recently. The stochastic multicloud model (SMCM) CP in particular mimics the dynamical interactions of multiple cloud types that characterize organized tropical convection. Here, the SMCM is used to modify the Zhang‐McFarlane (ZM) CP by changing the way in which the bulk mass flux and bulk entrainment and detrainment rates are calculated. This is done by introducing a stochastic ensemble of plumes characterized by randomly varying detrainment level distributions based on the cloud area fraction of the SMCM. The SMCM is here extended to include shallow cumulus clouds resulting in a unified shallow‐deep CP. The new stochastic multicloud plume CP is validated against the control ZM scheme in the context of the single column Community Climate Model of the National Center for Atmospheric Research using data from both tropical ocean and midlatitude land convection. Some key features of the SMCM CP such as it capability to represent the tri‐modal nature of organized convection are emphasized. AU - Khouider, B. AU - GOSWAMI, BIDYUT B AU - Phani, R. AU - Majda, A. J. ID - 14564 IS - 11 JF - Journal of Advances in Modeling Earth Systems KW - General Earth and Planetary Sciences KW - Environmental Chemistry KW - Global and Planetary Change TI - A shallow‐deep unified stochastic mass flux cumulus parameterization in the single column community climate model VL - 15 ER - TY - JOUR AB - Experiments have shown that charge distributions of granular materials are non-Gaussian, with broad tails that indicate many particles with high charge. This observation has consequences for the behavior of granular materials in many settings, and may bear relevance to the underlying charge transfer mechanism. However, there is the unaddressed possibility that broad tails arise due to experimental uncertainties, as determining the shapes of tails is nontrivial. Here we show that measurement uncertainties can indeed account for most of the tail broadening previously observed. The clue that reveals this is that distributions are sensitive to the electric field at which they are measured; ones measured at low (high) fields have larger (smaller) tails. Accounting for sources of uncertainty, we reproduce this broadening in silico. Finally, we use our results to back out the true charge distribution without broadening, which we find is still non-Guassian, though with substantially different behavior at the tails and indicating significantly fewer highly charged particles. These results have implications in many natural settings where electrostatic interactions, especially among highly charged particles, strongly affect granular behavior. AU - Mujica, Nicolás AU - Waitukaitis, Scott R ID - 12789 IS - 3 JF - Physical Review E SN - 2470-0045 TI - Accurate determination of the shapes of granular charge distributions VL - 107 ER - TY - CONF AB - We consider a natural problem dealing with weighted packet selection across a rechargeable link, which e.g., finds applications in cryptocurrency networks. The capacity of a link (u, v) is determined by how much nodes u and v allocate for this link. Specifically, the input is a finite ordered sequence of packets that arrive in both directions along a link. Given (u, v) and a packet of weight x going from u to v, node u can either accept or reject the packet. If u accepts the packet, the capacity on link (u, v) decreases by x. Correspondingly, v’s capacity on (u, v) increases by x. If a node rejects the packet, this will entail a cost affinely linear in the weight of the packet. A link is “rechargeable” in the sense that the total capacity of the link has to remain constant, but the allocation of capacity at the ends of the link can depend arbitrarily on the nodes’ decisions. The goal is to minimise the sum of the capacity injected into the link and the cost of rejecting packets. We show that the problem is NP-hard, but can be approximated efficiently with a ratio of (1+ε)⋅(1+3–√) for some arbitrary ε>0. . AU - Schmid, Stefan AU - Svoboda, Jakub AU - Yeo, Michelle X ID - 13238 SN - 0302-9743 T2 - SIROCCO 2023: Structural Information and Communication Complexity TI - Weighted packet selection for rechargeable links in cryptocurrency networks: Complexity and approximation VL - 13892 ER - TY - THES AB - Payment channel networks are a promising approach to improve the scalability bottleneck of cryptocurrencies. Two design principles behind payment channel networks are efficiency and privacy. Payment channel networks improve efficiency by allowing users to transact in a peer-to-peer fashion along multi-hop routes in the network, avoiding the lengthy process of consensus on the blockchain. Transacting over payment channel networks also improves privacy as these transactions are not broadcast to the blockchain. Despite the influx of recent protocols built on top of payment channel networks and their analysis, a common shortcoming of many of these protocols is that they typically focus only on either improving efficiency or privacy, but not both. Another limitation on the efficiency front is that the models used to model actions, costs and utilities of users are limited or come with unrealistic assumptions. This thesis aims to address some of the shortcomings of recent protocols and algorithms on payment channel networks, particularly in their privacy and efficiency aspects. We first present a payment route discovery protocol based on hub labelling and private information retrieval that hides the route query and is also efficient. We then present a rebalancing protocol that formulates the rebalancing problem as a linear program and solves the linear program using multiparty computation so as to hide the channel balances. The rebalancing solution as output by our protocol is also globally optimal. We go on to develop more realistic models of the action space, costs, and utilities of both existing and new users that want to join the network. In each of these settings, we also develop algorithms to optimise the utility of these users with good guarantees on the approximation and competitive ratios. AU - Yeo, Michelle X ID - 14506 SN - 2663 - 337X TI - Advances in efficiency and privacy in payment channel network analysis ER - TY - CONF AB - Payment channel networks (PCNs) are a promising solution to the scalability problem of cryptocurrencies. Any two users connected by a payment channel in the network can theoretically send an unbounded number of instant, costless transactions between them. Users who are not directly connected can also transact with each other in a multi-hop fashion. In this work, we study the incentive structure behind the creation of payment channel networks, particularly from the point of view of a single user that wants to join the network. We define a utility function for a new user in terms of expected revenue, expected fees, and the cost of creating channels, and then provide constant factor approximation algorithms that optimise the utility function given a certain budget. Additionally, we take a step back from a single user to the whole network and examine the parameter spaces under which simple graph topologies form a Nash equilibrium. AU - Avarikioti, Zeta AU - Lizurej, Tomasz AU - Michalak, Tomasz AU - Yeo, Michelle X ID - 14490 SN - 9798350339864 T2 - 43rd International Conference on Distributed Computing Systems TI - Lightning creation games VL - 2023 ER - TY - THES AB - Most motions of many-body systems at any scale in nature with sufficient degrees of freedom tend to be chaotic; reaching from the orbital motion of planets, the air currents in our atmosphere, down to the water flowing through our pipelines or the movement of a population of bacteria. To the observer it is therefore intriguing when a moving collective exhibits order. Collective motion of flocks of birds, schools of fish or swarms of self-propelled particles or robots have been studied extensively over the past decades but the mechanisms involved in the transition from chaos to order remain unclear. Here, the interactions, that in most systems give rise to chaos, sustain order. In this thesis we investigate mechanisms that preserve, destabilize or lead to the ordered state. We show that endothelial cells migrating in circular confinements transition to a collective rotating state and concomitantly synchronize the frequencies of nucleating actin waves within individual cells. Consequently, the frequency dependent cell migration speed uniformizes across the population. Complementary to the WAVE dependent nucleation of traveling actin waves, we show that in leukocytes the actin polymerization depending on WASp generates pushing forces locally at stationary patches. Next, in pipe flows, we study methods to disrupt the self–sustaining cycle of turbulence and therefore relaminarize the flow. While we find in pulsating flow conditions that turbulence emerges through a helical instability during the decelerating phase. Finally, we show quantitatively in brain slices of mice that wild-type control neurons can compensate the migratory deficits of a genetically modified neuronal sub–population in the developing cortex. AU - Riedl, Michael ID - 12726 SN - 2663-337X TI - Synchronization in collectively moving active matter ER - TY - THES AB - Most motions of many-body systems at any scale in nature with sufficient degrees of freedom tend to be chaotic; reaching from the orbital motion of planets, the air currents in our atmosphere, down to the water flowing through our pipelines or the movement of a population of bacteria. To the observer it is therefore intriguing when a moving collective exhibits order. Collective motion of flocks of birds, schools of fish or swarms of self-propelled particles or robots have been studied extensively over the past decades but the mechanisms involved in the transition from chaos to order remain unclear. Here, the interactions, that in most systems give rise to chaos, sustain order. In this thesis we investigate mechanisms that preserve, destabilize or lead to the ordered state. We show that endothelial cells migrating in circular confinements transition to a collective rotating state and concomitantly synchronize the frequencies of nucleating actin waves within individual cells. Consequently, the frequency dependent cell migration speed uniformizes across the population. Complementary to the WAVE dependent nucleation of traveling actin waves, we show that in leukocytes the actin polymerization depending on WASp generates pushing forces locally at stationary patches. Next, in pipe flows, we study methods to disrupt the self--sustaining cycle of turbulence and therefore relaminarize the flow. While we find in pulsating flow conditions that turbulence emerges through a helical instability during the decelerating phase. Finally, we show quantitatively in brain slices of mice that wild-type control neurons can compensate the migratory deficits of a genetically modified neuronal sub--population in the developing cortex. AU - Riedl, Michael ID - 14530 KW - Synchronization KW - Collective Movement KW - Active Matter KW - Cell Migration KW - Active Colloids SN - 2663 - 337X TI - Synchronization in collectively moving active matter ER - TY - THES AB - Superconductor-semiconductor heterostructures currently capture a significant amount of research interest and they serve as the physical platform in many proposals towards topological quantum computation. Despite being under extensive investigations, historically using transport techniques, the basic properties of the interface between the superconductor and the semiconductor remain to be understood. In this thesis, two separate studies on the Al-InAs heterostructures are reported with the first focusing on the physics of the material motivated by the emergence of a new phase, the Bogoliubov-Fermi surface. The second focuses on a technological application, a gate-tunable Josephson parametric amplifier. In the first study, we investigate the hypothesized unconventional nature of the induced superconductivity at the interface between the Al thin film and the InAs quantum well. We embed a two-dimensional Al-InAs hybrid system in a resonant microwave circuit allowing measurements of change in inductance. The behaviour of the resonance in a range of temperature and in-plane magnetic field has been studied and compared with the theory of conventional s-wave superconductor and a two-component theory that includes both contribution of the $s$-wave pairing in Al and the intraband $p \pm ip$ pairing in InAs. Measuring the temperature dependence of resonant frequency, no discrepancy is found between data and the conventional theory. We observe the breakdown of superconductivity due to an applied magnetic field which contradicts the conventional theory. In contrast, the data can be captured quantitatively by fitting to a two-component model. We find the evidence of the intraband $p \pm ip$ pairing in the InAs and the emergence of the Bogoliubov-Fermi surfaces due to magnetic field with the characteristic value $B^* = 0.33~\mathrm{T}$. From the fits, the sheet resistance of Al, the carrier density and mobility in InAs are determined. By systematically studying the anisotropy of the circuit response, we find weak anisotropy for $B < B^*$ and increasingly strong anisotropy for $B > B^*$ resulting in a pronounced two-lobe structure in polar plot of frequency versus field angle. Strong resemblance between the field dependence of dissipation and superfluid density hints at a hidden signature of the Bogoliubov-Fermi surface that is burried in the dissipation data. In the second study, we realize a parametric amplifier with a Josephson field effect transistor as the active element. The device's modest construction consists of a gated SNS weak link embedded at the center of a coplanar waveguide resonator. By applying a gate voltage, the resonant frequency is field-effect tunable over a range of 2 GHz. Modelling the JoFET minimally as a parallel RL circuit, the dissipation introduced by the JoFET can be quantitatively related to the gate voltage. We observed gate-tunable Kerr nonlinearity qualitatively in line with expectation. The JoFET amplifier has 20 dB of gain, 4 MHz of instantaneous bandwidth, and a 1dB compression point of -125.5 dBm when operated at a fixed resonant frequency. In general, the signal-to-noise ratio is improved by 5-7 dB when the JoFET amplifier is activated compared. The noise of the measurement chain and insertion loss of relevant circuit elements are calibrated to determine the expected and the real noise performance of the JoFET amplifier. As a quantification of the noise performance, the measured total input-referred noise of the JoFET amplifier is in good agreement with the estimated expectation which takes device loss into account. We found that the noise performance of the device reported in this document approaches one photon of total input-referred added noise which is the quantum limit imposed in nondegenerate parametric amplifier. AU - Phan, Duc T ID - 14547 KW - superconductor-semiconductor KW - superconductivity KW - Al KW - InAs KW - p-wave KW - superconductivity KW - JPA KW - microwave SN - 2663 - 337X TI - Resonant microwave spectroscopy of Al-InAs ER - TY - JOUR AB - We build a parametric amplifier with a Josephson field-effect transistor (JoFET) as the active element. The resonant frequency of the device is field-effect tunable over a range of 2 GHz. The JoFET amplifier has 20 dB of gain, 4 MHz of instantaneous bandwidth, and a 1-dB compression point of -125.5 dBm when operated at a fixed resonance frequency. AU - Phan, Duc T AU - Falthansl-Scheinecker, Paul AU - Mishra, Umang AU - Strickland, W. M. AU - Langone, D. AU - Shabani, J. AU - Higginbotham, Andrew P ID - 13264 IS - 6 JF - Physical Review Applied TI - Gate-tunable superconductor-semiconductor parametric amplifier VL - 19 ER - TY - GEN AB - Clathrin-mediated endocytosis (CME) is vital for the regulation of plant growth and development by controlling plasma membrane protein composition and cargo uptake. CME relies on the precise recruitment of regulators for vesicle maturation and release. Homologues of components of mammalian vesicle scission are strong candidates to be part of the scissin machinery in plants, but the precise roles of these proteins in this process is not fully understood. Here, we characterised the roles of Plant Dynamin-Related Proteins 2 (DRP2s) and SH3-domain containing protein 2 (SH3P2), the plant homologue to Dynamins’ recruiters, like Endophilin and Amphiphysin, in the CME by combining high-resolution imaging of endocytic events in vivo and characterisation of the purified proteins in vitro. Although DRP2s and SH3P2 arrive similarly late during CME and physically interact, genetic analysis of the Dsh3p1,2,3 triple-mutant and complementation assays with non-SH3P2-interacting DRP2 variants suggests that SH3P2 does not directly recruit DRP2s to the site of endocytosis. These observations imply that despite the presence of many well-conserved endocytic components, plants have acquired a distinct mechanism for CME. One Sentence Summary In contrast to predictions based on mammalian systems, plant Dynamin-related proteins 2 are recruited to the site of Clathrin-mediated endocytosis independently of BAR-SH3 proteins. AU - Gnyliukh, Nataliia AU - Johnson, Alexander J AU - Nagel, Marie-Kristin AU - Monzer, Aline AU - Hlavata, Annamaria AU - Isono, Erika AU - Loose, Martin AU - Friml, Jiří ID - 14591 T2 - bioRxiv TI - Role of dynamin-related proteins 2 and SH3P2 in clathrin-mediated endocytosis in plants ER - TY - JOUR AB - We introduce a compact, intuitive procedural graph representation for cellular metamaterials, which are small-scale, tileable structures that can be architected to exhibit many useful material properties. Because the structures’ “architectures” vary widely—with elements such as beams, thin shells, and solid bulks—it is difficult to explore them using existing representations. Generic approaches like voxel grids are versatile, but it is cumbersome to represent and edit individual structures; architecture-specific approaches address these issues, but are incompatible with one another. By contrast, our procedural graph succinctly represents the construction process for any structure using a simple skeleton annotated with spatially varying thickness. To express the highly constrained triply periodic minimal surfaces (TPMS) in this manner, we present the first fully automated version of the conjugate surface construction method, which allows novices to create complex TPMS from intuitive input. We demonstrate our representation’s expressiveness, accuracy, and compactness by constructing a wide range of established structures and hundreds of novel structures with diverse architectures and material properties. We also conduct a user study to verify our representation’s ease-of-use and ability to expand engineers’ capacity for exploration. AU - Makatura, Liane AU - Wang, Bohan AU - Chen, Yi-Lu AU - Deng, Bolei AU - Wojtan, Christopher J AU - Bickel, Bernd AU - Matusik, Wojciech ID - 14628 IS - 5 JF - ACM Transactions on Graphics KW - Computer Graphics and Computer-Aided Design SN - 0730-0301 TI - Procedural metamaterials: A unified procedural graph for metamaterial design VL - 42 ER - TY - GEN AB - Transcription by RNA polymerase II (Pol II) can be repressed by noncoding RNA, including the human RNA Alu. However, the mechanism by which endogenous RNAs repress transcription remains unclear. Here we present cryo-electron microscopy structures of Pol II bound to Alu RNA, which reveal that Alu RNA mimics how DNA and RNA bind to Pol II during transcription elongation. Further, we show how domains of the general transcription factor TFIIF affect complex dynamics and control repressive activity. Together, we reveal how a non-coding RNA can regulate mammalian gene expression. AU - Tluckova, Katarina AU - Testa Salmazo, Anita P AU - Bernecky, Carrie A ID - 14644 TI - Mechanism of mammalian transcriptional repression by noncoding RNA ER -