@article{1292,
abstract = {We give explicit formulas and algorithms for the computation of the Thurston–Bennequin invariant of a nullhomologous Legendrian knot on a page of a contact open book and on Heegaard surfaces in convex position. Furthermore, we extend the results to rationally nullhomologous knots in arbitrary 3-manifolds.},
author = {Durst, Sebastian and Kegel, Marc and Klukas, Mirko D},
journal = {Acta Mathematica Hungarica},
number = {2},
pages = {441 -- 455},
publisher = {Springer},
title = {{Computing the Thurston–Bennequin invariant in open books}},
doi = {10.1007/s10474-016-0648-4},
volume = {150},
year = {2016},
}
@article{1293,
abstract = {For a graph G with p vertices the closed convex cone S⪰0(G) consists of all real positive semidefinite p×p matrices whose sparsity pattern is given by G, that is, those matrices with zeros in the off-diagonal entries corresponding to nonedges of G. The extremal rays of this cone and their associated ranks have applications to matrix completion problems, maximum likelihood estimation in Gaussian graphical models in statistics, and Gauss elimination for sparse matrices. While the maximum rank of an extremal ray in S⪰0(G), known as the sparsity order of G, has been characterized for different classes of graphs, we here study all possible extremal ranks of S⪰0(G). We investigate when the geometry of the (±1)-cut polytope of G yields a polyhedral characterization of the set of extremal ranks of S⪰0(G). For a graph G without K5 minors, we show that appropriately chosen normal vectors to the facets of the (±1)-cut polytope of G specify the off-diagonal entries of extremal matrices in S⪰0(G). We also prove that for appropriately chosen scalars the constant term of the linear equation of each facet-supporting hyperplane is the rank of its corresponding extremal matrix in S⪰0(G). Furthermore, we show that if G is series-parallel then this gives a complete characterization of all possible extremal ranks of S⪰0(G). Consequently, the sparsity order problem for series-parallel graphs can be solved in terms of polyhedral geometry.},
author = {Solus, Liam T and Uhler, Caroline and Yoshida, Ruriko},
journal = {Linear Algebra and Its Applications},
pages = {247 -- 275},
publisher = {Elsevier},
title = {{Extremal positive semidefinite matrices whose sparsity pattern is given by graphs without K5 minors}},
doi = {10.1016/j.laa.2016.07.026},
volume = {509},
year = {2016},
}
@article{1323,
abstract = {Mossy fiber synapses on CA3 pyramidal cells are 'conditional detonators' that reliably discharge postsynaptic targets. The 'conditional' nature implies that burst activity in dentate gyrus granule cells is required for detonation. Whether single unitary excitatory postsynaptic potentials (EPSPs) trigger spikes in CA3 neurons remains unknown. Mossy fiber synapses exhibit both pronounced short-term facilitation and uniquely large post-tetanic potentiation (PTP). We tested whether PTP could convert mossy fiber synapses from subdetonator into detonator mode, using a recently developed method to selectively and noninvasively stimulate individual presynaptic terminals in rat brain slices. Unitary EPSPs failed to initiate a spike in CA3 neurons under control conditions, but reliably discharged them after induction of presynaptic short-term plasticity. Remarkably, PTP switched mossy fiber synapses into full detonators for tens of seconds. Plasticity-dependent detonation may be critical for efficient coding, storage, and recall of information in the granule cell–CA3 cell network.},
author = {Vyleta, Nicholas and Borges Merjane, Carolina and Jonas, Peter M},
journal = {eLife},
publisher = {eLife Sciences Publications},
title = {{Plasticity-dependent, full detonation at hippocampal mossy fiber–CA3 pyramidal neuron synapses}},
doi = {10.7554/eLife.17977},
volume = {5},
year = {2016},
}
@inproceedings{1325,
abstract = {We study graphs and two-player games in which rewards are assigned to states, and the goal of the players is to satisfy or dissatisfy certain property of the generated outcome, given as a mean payoff property. Since the notion of mean-payoff does not reflect possible fluctuations from the mean-payoff along a run, we propose definitions and algorithms for capturing the stability of the system, and give algorithms for deciding if a given mean payoff and stability objective can be ensured in the system.},
author = {Brázdil, Tomáš and Forejt, Vojtěch and Kučera, Antonín and Novotny, Petr},
location = {Quebec City, Canada},
publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
title = {{Stability in graphs and games}},
doi = {10.4230/LIPIcs.CONCUR.2016.10},
volume = {59},
year = {2016},
}
@inproceedings{1326,
abstract = {Energy Markov Decision Processes (EMDPs) are finite-state Markov decision processes where each transition is assigned an integer counter update and a rational payoff. An EMDP configuration is a pair s(n), where s is a control state and n is the current counter value. The configurations are changed by performing transitions in the standard way. We consider the problem of computing a safe strategy (i.e., a strategy that keeps the counter non-negative) which maximizes the expected mean payoff. },
author = {Brázdil, Tomáš and Kučera, Antonín and Novotny, Petr},
location = {Chiba, Japan},
pages = {32 -- 49},
publisher = {Springer},
title = {{Optimizing the expected mean payoff in Energy Markov Decision Processes}},
doi = {10.1007/978-3-319-46520-3_3},
volume = {9938},
year = {2016},
}
@inproceedings{1327,
abstract = {We consider partially observable Markov decision processes (POMDPs) with a set of target states and positive integer costs associated with every transition. The traditional optimization objective (stochastic shortest path) asks to minimize the expected total cost until the target set is reached. We extend the traditional framework of POMDPs to model energy consumption, which represents a hard constraint. The energy levels may increase and decrease with transitions, and the hard constraint requires that the energy level must remain positive in all steps till the target is reached. First, we present a novel algorithm for solving POMDPs with energy levels, developing on existing POMDP solvers and using RTDP as its main method. Our second contribution is related to policy representation. For larger POMDP instances the policies computed by existing solvers are too large to be understandable. We present an automated procedure based on machine learning techniques that automatically extracts important decisions of the policy allowing us to compute succinct human readable policies. Finally, we show experimentally that our algorithm performs well and computes succinct policies on a number of POMDP instances from the literature that were naturally enhanced with energy levels. },
author = {Brázdil, Tomáš and Chatterjee, Krishnendu and Chmelik, Martin and Gupta, Anchit and Novotny, Petr},
booktitle = {Proceedings of the 15th International Conference on Autonomous Agents and Multiagent Systems},
location = {Singapore},
pages = {1465 -- 1466},
publisher = {ACM},
title = {{Stochastic shortest path with energy constraints in POMDPs}},
year = {2016},
}
@article{1328,
abstract = {Hole spins have gained considerable interest in the past few years due to their potential for fast electrically controlled qubits. Here, we study holes confined in Ge hut wires, a so-far unexplored type of nanostructure. Low-temperature magnetotransport measurements reveal a large anisotropy between the in-plane and out-of-plane g-factors of up to 18. Numerical simulations verify that this large anisotropy originates from a confined wave function of heavy-hole character. A light-hole admixture of less than 1% is estimated for the states of lowest energy, leading to a surprisingly large reduction of the out-of-plane g-factors compared with those for pure heavy holes. Given this tiny light-hole contribution, the spin lifetimes are expected to be very long, even in isotopically nonpurified samples.},
author = {Watzinger, Hannes and Kloeffel, Christoph and Vukusic, Lada and Rossell, Marta and Sessi, Violetta and Kukucka, Josip and Kirchschlager, Raimund and Lausecker, Elisabeth and Truhlar, Alisha and Glaser, Martin and Rastelli, Armando and Fuhrer, Andreas and Loss, Daniel and Katsaros, Georgios},
journal = {Nano Letters},
number = {11},
pages = {6879 -- 6885},
publisher = {American Chemical Society},
title = {{Heavy-hole states in germanium hut wires}},
doi = {10.1021/acs.nanolett.6b02715},
volume = {16},
year = {2016},
}
@article{1329,
abstract = {Daphnia species have become models for ecological genomics and exhibit interesting features, such as high phenotypic plasticity and a densely packed genome with many lineage-specific genes. They are also cyclic parthenogenetic, with alternating asexual and sexual cycles and environmental sex determination. Here, we present a de novo transcriptome assembly of over 32,000 D. galeata genes and use it to investigate gene expression in females and spontaneously produced males of two clonal lines derived from lakes in Germany and the Czech Republic. We find that only a low percentage (18%) of genes shows sex-biased expression and that there are many more female-biased gene (FBG) than male-biased gene (MBG). Furthermore, FBGs tend to be more conserved between species than MBGs in both sequence and expression. These patterns may be a consequence of cyclic parthenogenesis leading to a relaxation of purifying selection on MBGs. The two clonal lines show considerable differences in both number and identity of sex-biased genes, suggesting that they may have reproductive strategies differing in their investment in sexual reproduction. Orthologs of key genes in the sex determination and juvenile hormone pathways, which are thought to be important for the transition from asexual to sexual reproduction, are present in D. galeata and highly conserved among Daphnia species.},
author = {Huylmans, Ann K and López Ezquerra, Alberto and Parsch, John and Cordellier, Mathilde},
journal = {Genome Biology and Evolution},
number = {10},
pages = {3120 -- 3139},
publisher = {Oxford University Press},
title = {{De novo transcriptome assembly and sex-biased gene expression in the cyclical parthenogenetic Daphnia galeata}},
doi = {10.1093/gbe/evw221},
volume = {8},
year = {2016},
}
@article{1330,
abstract = {In this paper we investigate the existence of closed billiard trajectories in not necessarily smooth convex bodies. In particular, we show that if a body K ⊂ Rd has the property that the tangent cone of every non-smooth point q ∉ ∂K is acute (in a certain sense), then there is a closed billiard trajectory in K.},
author = {Akopyan, Arseniy and Balitskiy, Alexey},
journal = {Israel Journal of Mathematics},
number = {2},
pages = {833 -- 845},
publisher = {Springer},
title = {{Billiards in convex bodies with acute angles}},
doi = {10.1007/s11856-016-1429-z},
volume = {216},
year = {2016},
}
@article{1332,
abstract = {Antibiotic-sensitive and -resistant bacteria coexist in natural environments with low, if detectable, antibiotic concentrations. Except possibly around localized antibiotic sources, where resistance can provide a strong advantage, bacterial fitness is dominated by stresses unaffected by resistance to the antibiotic. How do such mixed and heterogeneous conditions influence the selective advantage or disadvantage of antibiotic resistance? Here we find that sub-inhibitory levels of tetracyclines potentiate selection for or against tetracycline resistance around localized sources of almost any toxin or stress. Furthermore, certain stresses generate alternating rings of selection for and against resistance around a localized source of the antibiotic. In these conditions, localized antibiotic sources, even at high strengths, can actually produce a net selection against resistance to the antibiotic. Our results show that interactions between the effects of an antibiotic and other stresses in inhomogeneous environments can generate pervasive, complex patterns of selection both for and against antibiotic resistance.},
author = {Chait, Remy P and Palmer, Adam and Yelin, Idan and Kishony, Roy},
journal = {Nature Communications},
publisher = {Nature Publishing Group},
title = {{Pervasive selection for and against antibiotic resistance in inhomogeneous multistress environments}},
doi = {10.1038/ncomms10333},
volume = {7},
year = {2016},
}