@inbook{562, abstract = {Primary neuronal cell culture preparations are widely used to investigate synaptic functions. This chapter describes a detailed protocol for the preparation of a neuronal cell culture in which giant calyx-type synaptic terminals are formed. This chapter also presents detailed protocols for utilizing the main technical advantages provided by such a preparation, namely, labeling and imaging of synaptic organelles and electrophysiological recordings directly from presynaptic terminals.}, author = {Dimitrov, Dimitar and Guillaud, Laurent and Eguchi, Kohgaku and Takahashi, Tomoyuki}, booktitle = {Neurotrophic Factors}, editor = {Skaper, Stephen D.}, pages = {201 -- 215}, publisher = {Springer}, title = {{Culture of mouse giant central nervous system synapses and application for imaging and electrophysiological analyses}}, doi = {10.1007/978-1-4939-7571-6_15}, volume = {1727}, year = {2018}, } @article{563, abstract = {In continuous populations with local migration, nearby pairs of individuals have on average more similar genotypes than geographically well separated pairs. A barrier to gene flow distorts this classical pattern of isolation by distance. Genetic similarity is decreased for sample pairs on different sides of the barrier and increased for pairs on the same side near the barrier. Here, we introduce an inference scheme that utilizes this signal to detect and estimate the strength of a linear barrier to gene flow in two-dimensions. We use a diffusion approximation to model the effects of a barrier on the geographical spread of ancestry backwards in time. This approach allows us to calculate the chance of recent coalescence and probability of identity by descent. We introduce an inference scheme that fits these theoretical results to the geographical covariance structure of bialleleic genetic markers. It can estimate the strength of the barrier as well as several demographic parameters. We investigate the power of our inference scheme to detect barriers by applying it to a wide range of simulated data. We also showcase an example application to a Antirrhinum majus (snapdragon) flower color hybrid zone, where we do not detect any signal of a strong genome wide barrier to gene flow.}, author = {Ringbauer, Harald and Kolesnikov, Alexander and Field, David and Barton, Nicholas H}, journal = {Genetics}, number = {3}, pages = {1231--1245}, publisher = {Genetics Society of America}, title = {{Estimating barriers to gene flow from distorted isolation-by-distance patterns}}, doi = {10.1534/genetics.117.300638}, volume = {208}, year = {2018}, } @article{564, abstract = {Maladapted individuals can only colonise a new habitat if they can evolve a positive growth rate fast enough to avoid extinction, a process known as evolutionary rescue. We treat log fitness at low density in the new habitat as a single polygenic trait and thus use the infinitesimal model to follow the evolution of the growth rate; this assumes that the trait values of offspring of a sexual union are normally distributed around the mean of the parents’ trait values, with variance that depends only on the parents’ relatedness. The probability that a single migrant can establish depends on just two parameters: the mean and genetic variance of the trait in the source population. The chance of success becomes small if migrants come from a population with mean growth rate in the new habitat more than a few standard deviations below zero; this chance depends roughly equally on the probability that the initial founder is unusually fit, and on the subsequent increase in growth rate of its offspring as a result of selection. The loss of genetic variation during the founding event is substantial, but highly variable. With continued migration at rate M, establishment is inevitable; when migration is rare, the expected time to establishment decreases inversely with M. However, above a threshold migration rate, the population may be trapped in a ‘sink’ state, in which adaptation is held back by gene flow; above this threshold, the expected time to establishment increases exponentially with M. This threshold behaviour is captured by a deterministic approximation, which assumes a Gaussian distribution of the trait in the founder population with mean and variance evolving deterministically. By assuming a constant genetic variance, we also develop a diffusion approximation for the joint distribution of population size and trait mean, which extends to include stabilising selection and density regulation. Divergence of the population from its ancestors causes partial reproductive isolation, which we measure through the reproductive value of migrants into the newly established population.}, author = {Barton, Nicholas H and Etheridge, Alison}, journal = {Theoretical Population Biology}, number = {7}, pages = {110--127}, publisher = {Academic Press}, title = {{Establishment in a new habitat by polygenic adaptation}}, doi = {10.1016/j.tpb.2017.11.007}, volume = {122}, year = {2018}, } @article{565, abstract = {We re-examine the model of Kirkpatrick and Barton for the spread of an inversion into a local population. This model assumes that local selection maintains alleles at two or more loci, despite immigration of alternative alleles at these loci from another population. We show that an inversion is favored because it prevents the breakdown of linkage disequilibrium generated by migration; the selective advantage of an inversion is proportional to the amount of recombination between the loci involved, as in other cases where inversions are selected for. We derive expressions for the rate of spread of an inversion; when the loci covered by the inversion are tightly linked, these conditions deviate substantially from those proposed previously, and imply that an inversion can then have only a small advantage. }, author = {Charlesworth, Brian and Barton, Nicholas H}, journal = {Genetics}, number = {1}, pages = {377 -- 382}, publisher = {Genetics }, title = {{The spread of an inversion with migration and selection}}, doi = {10.1534/genetics.117.300426}, volume = {208}, year = {2018}, } @article{566, abstract = {We consider large random matrices X with centered, independent entries which have comparable but not necessarily identical variances. Girko's circular law asserts that the spectrum is supported in a disk and in case of identical variances, the limiting density is uniform. In this special case, the local circular law by Bourgade et. al. [11,12] shows that the empirical density converges even locally on scales slightly above the typical eigenvalue spacing. In the general case, the limiting density is typically inhomogeneous and it is obtained via solving a system of deterministic equations. Our main result is the local inhomogeneous circular law in the bulk spectrum on the optimal scale for a general variance profile of the entries of X. }, author = {Alt, Johannes and Erdös, László and Krüger, Torben H}, journal = {Annals Applied Probability }, number = {1}, pages = {148--203}, publisher = {Institute of Mathematical Statistics}, title = {{Local inhomogeneous circular law}}, doi = {10.1214/17-AAP1302}, volume = {28}, year = {2018}, } @article{5672, abstract = {The release of IgM is the first line of an antibody response and precedes the generation of high affinity IgG in germinal centers. Once secreted by freshly activated plasmablasts, IgM is released into the efferent lymph of reactive lymph nodes as early as 3 d after immunization. As pentameric IgM has an enormous size of 1,000 kD, its diffusibility is low, and one might wonder how it can pass through the densely lymphocyte-packed environment of a lymph node parenchyma in order to reach its exit. In this issue of JEM, Thierry et al. show that, in order to reach the blood stream, IgM molecules take a specific micro-anatomical route via lymph node conduits.}, author = {Reversat, Anne and Sixt, Michael K}, issn = {00221007}, journal = {Journal of Experimental Medicine}, number = {12}, pages = {2959--2961}, publisher = {Rockefeller University Press}, title = {{IgM's exit route}}, doi = {10.1084/jem.20181934}, volume = {215}, year = {2018}, } @article{5673, abstract = {Cell polarity, manifested by the localization of proteins to distinct polar plasma membrane domains, is a key prerequisite of multicellular life. In plants, PIN auxin transporters are prominent polarity markers crucial for a plethora of developmental processes. Cell polarity mechanisms in plants are distinct from other eukaryotes and still largely elusive. In particular, how the cell polarities are propagated and maintained following cell division remains unknown. Plant cytokinesis is orchestrated by the cell plate—a transient centrifugally growing endomembrane compartment ultimately forming the cross wall1. Trafficking of polar membrane proteins is typically redirected to the cell plate, and these will consequently have opposite polarity in at least one of the daughter cells2–5. Here, we provide mechanistic insights into post-cytokinetic re-establishment of cell polarity as manifested by the apical, polar localization of PIN2. We show that the apical domain is defined in a cell-intrinsic manner and that re-establishment of PIN2 localization to this domain requires de novo protein secretion and endocytosis, but not basal-to-apical transcytosis. Furthermore, we identify a PINOID-related kinase WAG1, which phosphorylates PIN2 in vitro6 and is transcriptionally upregulated specifically in dividing cells, as a crucial regulator of post-cytokinetic PIN2 polarity re-establishment.}, author = {Glanc, Matous and Fendrych, Matyas and Friml, Jirí}, issn = {2055-0278}, journal = {Nature Plants}, number = {12}, pages = {1082--1088}, publisher = {Nature Research}, title = {{Mechanistic framework for cell-intrinsic re-establishment of PIN2 polarity after cell division}}, doi = {10.1038/s41477-018-0318-3}, volume = {4}, year = {2018}, } @article{5676, abstract = {In epithelial tissues, cells tightly connect to each other through cell–cell junctions, but they also present the remarkable capacity of reorganizing themselves without compromising tissue integrity. Upon injury, simple epithelia efficiently resolve small lesions through the action of actin cytoskeleton contractile structures at the wound edge and cellular rearrangements. However, the underlying mechanisms and how they cooperate are still poorly understood. In this study, we combine live imaging and theoretical modeling to reveal a novel and indispensable role for occluding junctions (OJs) in this process. We demonstrate that OJ loss of function leads to defects in wound-closure dynamics: instead of contracting, wounds dramatically increase their area. OJ mutants exhibit phenotypes in cell shape, cellular rearrangements, and mechanical properties as well as in actin cytoskeleton dynamics at the wound edge. We propose that OJs are essential for wound closure by impacting on epithelial mechanics at the tissue level, which in turn is crucial for correct regulation of the cellular events occurring at the wound edge.}, author = {Carvalho, Lara and Patricio, Pedro and Ponte, Susana and Heisenberg, Carl-Philipp J and Almeida, Luis and Nunes, André S. and Araújo, Nuno A.M. and Jacinto, Antonio}, issn = {00219525}, journal = {Journal of Cell Biology}, number = {12}, pages = {4267--4283}, publisher = {Rockefeller University Press}, title = {{Occluding junctions as novel regulators of tissue mechanics during wound repair}}, doi = {10.1083/jcb.201804048}, volume = {217}, year = {2018}, } @article{5677, abstract = {Recently, contract-based design has been proposed as an “orthogonal” approach that complements system design methodologies proposed so far to cope with the complexity of system design. Contract-based design provides a rigorous scaffolding for verification, analysis, abstraction/refinement, and even synthesis. A number of results have been obtained in this domain but a unified treatment of the topic that can help put contract-based design in perspective was missing. This monograph intends to provide such a treatment where contracts are precisely defined and characterized so that they can be used in design methodologies with no ambiguity. In particular, this monograph identifies the essence of complex system design using contracts through a mathematical “meta-theory”, where all the properties of the methodology are derived from a very abstract and generic notion of contract. We show that the meta-theory provides deep and illuminating links with existing contract and interface theories, as well as guidelines for designing new theories. Our study encompasses contracts for both software and systems, with emphasis on the latter. We illustrate the use of contracts with two examples: requirement engineering for a parking garage management, and the development of contracts for timing and scheduling in the context of the Autosar methodology in use in the automotive sector.}, author = {Benveniste, Albert and Nickovic, Dejan and Caillaud, Benoît and Passerone, Roberto and Raclet, Jean Baptiste and Reinkemeier, Philipp and Sangiovanni-Vincentelli, Alberto and Damm, Werner and Henzinger, Thomas A and Larsen, Kim G.}, issn = {1551-3939}, journal = {Foundations and Trends in Electronic Design Automation}, number = {2-3}, pages = {124--400}, publisher = {Now Publishers}, title = {{Contracts for system design}}, doi = {10.1561/1000000053}, volume = {12}, year = {2018}, } @inproceedings{5679, abstract = {We study the almost-sure termination problem for probabilistic programs. First, we show that supermartingales with lower bounds on conditional absolute difference provide a sound approach for the almost-sure termination problem. Moreover, using this approach we can obtain explicit optimal bounds on tail probabilities of non-termination within a given number of steps. Second, we present a new approach based on Central Limit Theorem for the almost-sure termination problem, and show that this approach can establish almost-sure termination of programs which none of the existing approaches can handle. Finally, we discuss algorithmic approaches for the two above methods that lead to automated analysis techniques for almost-sure termination of probabilistic programs.}, author = {Huang, Mingzhang and Fu, Hongfei and Chatterjee, Krishnendu}, editor = {Ryu, Sukyoung}, isbn = {9783030027674}, issn = {03029743}, location = {Wellington, New Zealand}, pages = {181--201}, publisher = {Springer}, title = {{New approaches for almost-sure termination of probabilistic programs}}, doi = {10.1007/978-3-030-02768-1_11}, volume = {11275}, year = {2018}, } @techreport{5686, author = {Danowski, Patrick}, pages = {5}, title = {{An Austrian proposal for the Classification of Open Access Tuples (COAT) - Distinguish different Open Access types beyond colors}}, doi = {10.5281/zenodo.1244154}, year = {2018}, } @article{5751, abstract = {Because of the intrinsic randomness of the evolutionary process, a mutant with a fitness advantage has some chance to be selected but no certainty. Any experiment that searches for advantageous mutants will lose many of them due to random drift. It is therefore of great interest to find population structures that improve the odds of advantageous mutants. Such structures are called amplifiers of natural selection: they increase the probability that advantageous mutants are selected. Arbitrarily strong amplifiers guarantee the selection of advantageous mutants, even for very small fitness advantage. Despite intensive research over the past decade, arbitrarily strong amplifiers have remained rare. Here we show how to construct a large variety of them. Our amplifiers are so simple that they could be useful in biotechnology, when optimizing biological molecules, or as a diagnostic tool, when searching for faster dividing cells or viruses. They could also occur in natural population structures.}, author = {Pavlogiannis, Andreas and Tkadlec, Josef and Chatterjee, Krishnendu and Nowak, Martin A.}, issn = {2399-3642}, journal = {Communications Biology}, number = {1}, publisher = {Springer Nature}, title = {{Construction of arbitrarily strong amplifiers of natural selection using evolutionary graph theory}}, doi = {10.1038/s42003-018-0078-7}, volume = {1}, year = {2018}, } @misc{5757, abstract = {File S1. Variant Calling Format file of the ingroup: 197 haploid sequences of D. melanogaster from Zambia (Africa) aligned to the D. melanogaster 5.57 reference genome. File S2. Variant Calling Format file of the outgroup: 1 haploid sequence of D. simulans aligned to the D. melanogaster 5.57 reference genome. File S3. Annotations of each transcript in coding regions with SNPeff: Ps (# of synonymous polymorphic sites); Pn (# of non-synonymous polymorphic sites); Ds (# of synonymous divergent sites); Dn (# of non-synonymous divergent sites); DoS; ⍺ MK . All variants were included. File S4. Annotations of each transcript in non-coding regions with SNPeff: Ps (# of synonymous polymorphic sites); Pu (# of UTR polymorphic sites); Ds (# of synonymous divergent sites); Du (# of UTR divergent sites); DoS; ⍺ MK . All variants were included. File S5. Annotations of each transcript in coding regions with SNPGenie: Ps (# of synonymous polymorphic sites); πs (synonymous diversity); Ss_p (total # of synonymous sites in the polymorphism data); Pn (# of non-synonymous polymorphic sites); πn (non-synonymous diversity); Sn_p (total # of non-synonymous sites in the polymorphism data); Ds (# of synonymous divergent sites); ks (synonymous evolutionary rate); Ss_d (total # of synonymous sites in the divergence data); Dn (# of non-synonymous divergent sites); kn (non-synonymous evolutionary rate); Sn_d (total # of non- synonymous sites in the divergence data); DoS; ⍺ MK . All variants were included. File S6. Gene expression values (RPKM summed over all transcripts) for each sample. Values were quantile-normalized across all samples. File S7. Final dataset with all covariates, ⍺ MK , ωA MK and DoS for coding sites, excluding variants below 5% frequency. File S8. Final dataset with all covariates, ⍺ MK , ωA MK and DoS for non-coding sites, excluding variants below 5% frequency. File S9. Final dataset with all covariates, ⍺ EWK , ωA EWK and deleterious SFS for coding sites obtained with the Eyre-Walker and Keightley method on binned data and using all variants.}, author = {Fraisse, Christelle}, keywords = {(mal)adaptation, pleiotropy, selective constraint, evo-devo, gene expression, Drosophila melanogaster}, publisher = {Institute of Science and Technology Austria}, title = {{Supplementary Files for "Pleiotropy modulates the efficacy of selection in Drosophila melanogaster"}}, doi = {10.15479/at:ista:/5757}, year = {2018}, } @article{5767, abstract = {Cuprate superconductors have long been thought of as having strong electronic correlations but negligible spin-orbit coupling. Using spin- and angle-resolved photoemission spectroscopy, we discovered that one of the most studied cuprate superconductors, Bi2212, has a nontrivial spin texture with a spin-momentum locking that circles the Brillouin zone center and a spin-layer locking that allows states of opposite spin to be localized in different parts of the unit cell. Our findings pose challenges for the vast majority of models of cuprates, such as the Hubbard model and its variants, where spin-orbit interaction has been mostly neglected, and open the intriguing question of how the high-temperature superconducting state emerges in the presence of this nontrivial spin texture. }, author = {Gotlieb, Kenneth and Lin, Chiu-Yun and Serbyn, Maksym and Zhang, Wentao and Smallwood, Christopher L. and Jozwiak, Christopher and Eisaki, Hiroshi and Hussain, Zahid and Vishwanath, Ashvin and Lanzara, Alessandra}, issn = {1095-9203}, journal = {Science}, number = {6420}, pages = {1271--1275}, publisher = {American Association for the Advancement of Science}, title = {{Revealing hidden spin-momentum locking in a high-temperature cuprate superconductor}}, doi = {10.1126/science.aao0980}, volume = {362}, year = {2018}, } @article{5770, abstract = {Retroviruses assemble and bud from infected cells in an immature form and require proteolytic maturation for infectivity. The CA (capsid) domains of the Gag polyproteins assemble a protein lattice as a truncated sphere in the immature virion. Proteolytic cleavage of Gag induces dramatic structural rearrangements; a subset of cleaved CA subsequently assembles into the mature core, whose architecture varies among retroviruses. Murine leukemia virus (MLV) is the prototypical γ-retrovirus and serves as the basis of retroviral vectors, but the structure of the MLV CA layer is unknown. Here we have combined X-ray crystallography with cryoelectron tomography to determine the structures of immature and mature MLV CA layers within authentic viral particles. This reveals the structural changes associated with maturation, and, by comparison with HIV-1, uncovers conserved and variable features. In contrast to HIV-1, most MLV CA is used for assembly of the mature core, which adopts variable, multilayered morphologies and does not form a closed structure. Unlike in HIV-1, there is similarity between protein–protein interfaces in the immature MLV CA layer and those in the mature CA layer, and structural maturation of MLV could be achieved through domain rotations that largely maintain hexameric interactions. Nevertheless, the dramatic architectural change on maturation indicates that extensive disassembly and reassembly are required for mature core growth. The core morphology suggests that wrapping of the genome in CA sheets may be sufficient to protect the MLV ribonucleoprotein during cell entry.}, author = {Qu, Kun and Glass, Bärbel and Doležal, Michal and Schur, Florian and Murciano, Brice and Rein, Alan and Rumlová, Michaela and Ruml, Tomáš and Kräusslich, Hans-Georg and Briggs, John A. G.}, issn = {00278424}, journal = {Proceedings of the National Academy of Sciences}, number = {50}, pages = {E11751--E11760}, publisher = {Proceedings of the National Academy of Sciences}, title = {{Structure and architecture of immature and mature murine leukemia virus capsids}}, doi = {10.1073/pnas.1811580115}, volume = {115}, year = {2018}, } @article{5780, abstract = {Bioluminescence is found across the entire tree of life, conferring a spectacular set of visually oriented functions from attracting mates to scaring off predators. Half a dozen different luciferins, molecules that emit light when enzymatically oxidized, are known. However, just one biochemical pathway for luciferin biosynthesis has been described in full, which is found only in bacteria. Here, we report identification of the fungal luciferase and three other key enzymes that together form the biosynthetic cycle of the fungal luciferin from caffeic acid, a simple and widespread metabolite. Introduction of the identified genes into the genome of the yeast Pichia pastoris along with caffeic acid biosynthesis genes resulted in a strain that is autoluminescent in standard media. We analyzed evolution of the enzymes of the luciferin biosynthesis cycle and found that fungal bioluminescence emerged through a series of events that included two independent gene duplications. The retention of the duplicated enzymes of the luciferin pathway in nonluminescent fungi shows that the gene duplication was followed by functional sequence divergence of enzymes of at least one gene in the biosynthetic pathway and suggests that the evolution of fungal bioluminescence proceeded through several closely related stepping stone nonluminescent biochemical reactions with adaptive roles. The availability of a complete eukaryotic luciferin biosynthesis pathway provides several applications in biomedicine and bioengineering.}, author = {Kotlobay, Alexey A. and Sarkisyan, Karen and Mokrushina, Yuliana A. and Marcet-Houben, Marina and Serebrovskaya, Ekaterina O. and Markina, Nadezhda M. and Gonzalez Somermeyer, Louisa and Gorokhovatsky, Andrey Y. and Vvedensky, Andrey and Purtov, Konstantin V. and Petushkov, Valentin N. and Rodionova, Natalja S. and Chepurnyh, Tatiana V. and Fakhranurova, Liliia and Guglya, Elena B. and Ziganshin, Rustam and Tsarkova, Aleksandra S. and Kaskova, Zinaida M. and Shender, Victoria and Abakumov, Maxim and Abakumova, Tatiana O. and Povolotskaya, Inna S. and Eroshkin, Fedor M. and Zaraisky, Andrey G. and Mishin, Alexander S. and Dolgov, Sergey V. and Mitiouchkina, Tatiana Y. and Kopantzev, Eugene P. and Waldenmaier, Hans E. and Oliveira, Anderson G. and Oba, Yuichi and Barsova, Ekaterina and Bogdanova, Ekaterina A. and Gabaldón, Toni and Stevani, Cassius V. and Lukyanov, Sergey and Smirnov, Ivan V. and Gitelson, Josef I. and Kondrashov, Fyodor and Yampolsky, Ilia V.}, issn = {00278424}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {50}, pages = {12728--12732}, publisher = {National Academy of Sciences}, title = {{Genetically encodable bioluminescent system from fungi}}, doi = {10.1073/pnas.1803615115}, volume = {115}, year = {2018}, } @article{5787, abstract = {Branching morphogenesis remains a subject of abiding interest. Although much is known about the gene regulatory programs and signaling pathways that operate at the cellular scale, it has remained unclear how the macroscopic features of branched organs, including their size, network topology and spatial patterning, are encoded. Lately, it has been proposed that, these features can be explained quantitatively in several organs within a single unifying framework. Based on large- scale organ recon - structions and cell lineage tracing, it has been argued that morphogenesis follows from the collective dynamics of sublineage- restricted self- renewing progenitor cells, localized at ductal tips, that act cooperatively to drive a serial process of ductal elon - gation and stochastic tip bifurcation. By correlating differentiation or cell cycle exit with proximity to maturing ducts, this dynamic results in the specification of a com- plex network of defined density and statistical organization. These results suggest that, for several mammalian tissues, branched epithelial structures develop as a self- organized process, reliant upon a strikingly simple, but generic, set of local rules, without recourse to a rigid and deterministic sequence of genetically programmed events. Here, we review the basis of these findings and discuss their implications.}, author = {Hannezo, Edouard B and Simons, Benjamin D.}, issn = {00121592}, journal = {Development Growth and Differentiation}, number = {9}, pages = {512--521}, publisher = {Wiley}, title = {{Statistical theory of branching morphogenesis}}, doi = {10.1111/dgd.12570}, volume = {60}, year = {2018}, } @inproceedings{5788, abstract = {In two-player games on graphs, the players move a token through a graph to produce an infinite path, which determines the winner or payoff of the game. Such games are central in formal verification since they model the interaction between a non-terminating system and its environment. We study bidding games in which the players bid for the right to move the token. Two bidding rules have been defined. In Richman bidding, in each round, the players simultaneously submit bids, and the higher bidder moves the token and pays the other player. Poorman bidding is similar except that the winner of the bidding pays the “bank” rather than the other player. While poorman reachability games have been studied before, we present, for the first time, results on infinite-duration poorman games. A central quantity in these games is the ratio between the two players’ initial budgets. The questions we study concern a necessary and sufficient ratio with which a player can achieve a goal. For reachability objectives, such threshold ratios are known to exist for both bidding rules. We show that the properties of poorman reachability games extend to complex qualitative objectives such as parity, similarly to the Richman case. Our most interesting results concern quantitative poorman games, namely poorman mean-payoff games, where we construct optimal strategies depending on the initial ratio, by showing a connection with random-turn based games. The connection in itself is interesting, because it does not hold for reachability poorman games. We also solve the complexity problems that arise in poorman bidding games.}, author = {Avni, Guy and Henzinger, Thomas A and Ibsen-Jensen, Rasmus}, isbn = {9783030046118}, issn = {03029743}, location = {Oxford, UK}, pages = {21--36}, publisher = {Springer}, title = {{Infinite-duration poorman-bidding games}}, doi = {10.1007/978-3-030-04612-5_2}, volume = {11316}, year = {2018}, } @inproceedings{5791, abstract = {Due to data compression or low resolution, nearby vertices and edges of a graph drawing may be bundled to a common node or arc. We model such a “compromised” drawing by a piecewise linear map φ:G → ℝ. We wish to perturb φ by an arbitrarily small ε>0 into a proper drawing (in which the vertices are distinct points, any two edges intersect in finitely many points, and no three edges have a common interior point) that minimizes the number of crossings. An ε-perturbation, for every ε>0, is given by a piecewise linear map (Formula Presented), where with ||·|| is the uniform norm (i.e., sup norm). We present a polynomial-time solution for this optimization problem when G is a cycle and the map φ has no spurs (i.e., no two adjacent edges are mapped to overlapping arcs). We also show that the problem becomes NP-complete (i) when G is an arbitrary graph and φ has no spurs, and (ii) when φ may have spurs and G is a cycle or a union of disjoint paths.}, author = {Fulek, Radoslav and Tóth, Csaba D.}, isbn = {9783030044138}, location = {Barcelona, Spain}, pages = {229--241}, publisher = {Springer}, title = {{Crossing minimization in perturbed drawings}}, doi = {10.1007/978-3-030-04414-5_16}, volume = {11282 }, year = {2018}, } @article{5794, abstract = {We present an approach to interacting quantum many-body systems based on the notion of quantum groups, also known as q-deformed Lie algebras. In particular, we show that, if the symmetry of a free quantum particle corresponds to a Lie group G, in the presence of a many-body environment this particle can be described by a deformed group, Gq. Crucially, the single deformation parameter, q, contains all the information about the many-particle interactions in the system. We exemplify our approach by considering a quantum rotor interacting with a bath of bosons, and demonstrate that extracting the value of q from closed-form solutions in the perturbative regime allows one to predict the behavior of the system for arbitrary values of the impurity-bath coupling strength, in good agreement with nonperturbative calculations. Furthermore, the value of the deformation parameter allows one to predict at which coupling strengths rotor-bath interactions result in a formation of a stable quasiparticle. The approach based on quantum groups does not only allow for a drastic simplification of impurity problems, but also provides valuable insights into hidden symmetries of interacting many-particle systems.}, author = {Yakaboylu, Enderalp and Shkolnikov, Mikhail and Lemeshko, Mikhail}, issn = {00319007}, journal = {Physical Review Letters}, number = {25}, publisher = {American Physical Society}, title = {{Quantum groups as hidden symmetries of quantum impurities}}, doi = {10.1103/PhysRevLett.121.255302}, volume = {121}, year = {2018}, }